DR. RATIO
Intelligentsia Guild · Self-Proclaimed Mundanite
Build Guide – Best Relics, Light Cone & Teams
🎭 A-TIER — DEBUFF-GATED IMAGINARY FUA DPS 🎭✦ Available on Standard Banner · Free via Trailblaze Events
The Self-Proclaimed Mundanite · Intellect as a Weapon
Dr. Ratio — a candid and self-centered member of the Intelligentsia Guild who conceals his appearance behind a plaster sculpture mask, a man who demonstrated unparalleled intelligence and talent since youth yet now refers to himself as a “Mundanite,” who firmly believes intellect and creativity are not confined to geniuses and seeks to distribute knowledge to cure the disease named ignorance — is a 5-star Imaginary Hunt character and HSR’s original debuff-scaling FUA damage dealer. Released in Version 1.6 (December 2023), he held a dominant position in the meta until Feixiao arrived. As of HSR 4.0 (February 2026), he sits at a solid A-Tier — capable, accessible, and well-understood, but no longer the premier FUA DPS.
Dr. Ratio’s design is built around a single elegant premise: every debuff on the target improves him. His Talent grants a base 40% chance to fire a Follow-Up Attack after each Skill use — with every debuff on the enemy adding another +20%, reaching a guaranteed 100% FUA chance at 3+ debuffs. His Ultimate applies the Wiseman’s Folly debuff, which causes enemies to take additional Imaginary DMG when the FUA triggers. His signature LC’s Disputation grants +36% DMG and 24% DEF Ignore on FUAs after using Ultimate. The entire kit is a self-reinforcing debuff amplifier — the more debuffs his team applies, the more damage Dr. Ratio deals per action.
Prydwen’s February 2026 assessment is direct: “He was replaced as the premier FUA damage dealer by Feixiao, who can do what Dr. Ratio does, but better. His glory days have passed.” That said, Prydwen also notes he “works with a vast array of other characters, fitting in nicely among the rest of the roster” and is “guaranteed to swat everything away with little effort” with accessible options. He is an honest A-Tier: strong, reliable, and rewarding to play — just no longer the FUA king.
Meta Context — February 2026
- Prydwen (Jan 29 2026): Explicitly places Dr. Ratio at A-Tier in the FUA DPS category, noting he has been surpassed by Feixiao for the premier FUA spot. Quote: “He was replaced as the premier FUA damage dealer by Feixiao, who can do what Dr. Ratio does, but better. His glory days have passed.” However, Prydwen also confirms he is “absolutely fine and strong” with accessible LC options, and “guaranteed to swat everything away.”
- Game8 (Feb 2026): Rates Dr. Ratio 0 points in endgame tier lists for the current 4.0 cycle — reflecting that content this patch has not specifically favored his kit. His General rating remains higher due to his baseline competence in boss fights.
- Mobalytics: Describes him as “a stellar unit” for single-target content with his signature LC, noting his signature specifically is “exceptionally powerful on him” and meaningfully improves performance over accessible alternatives.
- GenshinLab (Feb 23 2026): Notes his tier can range from “SS to A” depending on his team — with premium setups approaching higher performance and accessible teams solidly in A range.
- AoE weakness: Like Moze, Dr. Ratio has essentially no AoE damage capability. His entire kit is single-target FUA — he cannot split damage between multiple enemies effectively and performs poorly in Pure Fiction wave content where AoE clearing is the priority.
- Debuff dependence: At fewer than 3 debuffs, Dr. Ratio loses his guaranteed FUA and his damage drops significantly. Building a team specifically to maintain 3+ debuffs on the target is a non-trivial requirement. This is the single most important build consideration for Dr. Ratio players.
- The honest case for building him: Dr. Ratio is accessible (Standard Banner and events), works with many characters in the roster, has a well-understood build with clear BiS options, and is fully capable of clearing all endgame content with proper investment. For players without Feixiao, he is the best available Imaginary FUA DPS by a meaningful margin.
Kit Breakdown — Debuff Scaling System
Dr. Ratio’s entire kit is built around a single design principle: the more debuffs on the target, the stronger he becomes. Here is the complete system:
- Talent (Cogito, Ergo Sum) — FUA Chance: After using Skill, Dr. Ratio has a base 40% chance to immediately fire a Follow-Up Attack. Each debuff on the target increases this chance by +20%. At 1 debuff: 60%. At 2 debuffs: 80%. At 3 debuffs: 100% guaranteed. Prydwen notes he needs “at least 3 times (but ideally 5)” debuffs to reach maximum potential.
- Signature LC (Baptism of Pure Thought) — CRIT DMG Scaling: Additional +8% CRIT DMG per debuff on the target, up to 3 stacks (+24% CRIT DMG at 3 debuffs). Debuffs increase both FUA trigger chance AND CRIT DMG simultaneously — making every additional debuff a compound damage multiplier.
- Ultimate — Wiseman’s Folly: The Ultimate inflicts Wiseman’s Folly on the enemy — when Dr. Ratio’s FUA hits a target with Wiseman’s Folly, the FUA deals additional Imaginary DMG. This turns every post-Ultimate FUA into an enhanced attack with a bonus damage proc. Always use Ultimate before the next Skill to maximise FUA damage.
- Disputation (Signature LC): After using Ultimate, Dr. Ratio gains Disputation for 2 turns: +36% DMG dealt + 24% DEF Ignore on FUAs at S1. The DEF Ignore is especially potent in high-DEF boss content — it applies specifically to FUAs, which are his primary damage vehicle.
- 5-debuff threshold (A4 trace — Ratio’s Enlightenment): The A4 trace provides an additional FUA damage bonus when the target has 5+ debuffs. While not as game-changing as the 3-debuff guarantee, teams that can stack 5 debuffs (Topaz’s multiple debuffs, Silver Wolf’s element implant + multiple debuffs, Jiaoqiu’s stacked Ashen Roast) push his ceiling significantly. Target 5 debuffs when team composition allows it.
- Imaginary Weakness: When Dr. Ratio attacks an enemy with Imaginary Weakness, the Toughness reduction applies and Break effects apply normally. He contributes Imaginary Toughness reduction with every Skill and FUA. Silver Wolf can implant Imaginary Weakness on enemies without it — making her the most synergistic debuffer-partner for guaranteed Imaginary Weakness in any fight.
FUA Trigger Chance — Debuff Count Visual
Standard rotation: Ensure 3+ debuffs are on the target (from teammates / LC) → Use Ultimate (Wiseman’s Folly on target + Disputation activated) → Use Skill immediately (FUA fires with Wiseman’s Folly active + Disputation’s +36% DMG + 24% DEF Ignore on FUA) → Use Basic Attack if SP is needed → Repeat.
Timing note: Disputation lasts 2 turns from Ultimate use. If Dr. Ratio uses Ultimate, then a support acts, then Dr. Ratio uses Skill — the Skill’s FUA fires in Turn 2 of Disputation. This is still active. The rotation window is generous — Ultimate → Skill within 2 turns is always achievable in normal play.
When Wiseman’s Folly and Disputation overlap: The FUA benefits from BOTH simultaneously — Wiseman’s Folly bonus Imaginary DMG triggers on top of Disputation’s +36% DMG and 24% DEF Ignore. This is Dr. Ratio’s peak single-target damage window. Always try to align Skill use with both effects active.
Building 3–5 Debuffs — Team Debuff Sources
Meeting the 3-debuff threshold is the most critical team-building requirement for Dr. Ratio. Here are the most reliable debuff sources available:
Best Light Cones
Baptism of Pure Thought
⭐⭐⭐⭐⭐ Signature — Best in Slot
Why it’s #1: Dr. Ratio’s signature is purpose-built for his debuff-scaling kit and provides three synergistic bonuses simultaneously:
1) Base CRIT DMG: +32% (at S1) — a strong flat CRIT DMG boost that applies to all Dr. Ratio attacks.
2) Scaling CRIT DMG: +8% per debuff on target (up to 3 stacks = +24% additional CRIT DMG at S1 with 3 debuffs). Combined with the base +32%, this reaches +56% total CRIT DMG from the LC alone when 3 debuffs are active. Every debuff the team applies is simultaneously increasing FUA chance (from Talent) AND CRIT DMG (from LC) — the multiplicative compound is enormous.
3) Disputation (after Ultimate): +36% DMG + 24% DEF Ignore on FUAs for 2 turns. Prydwen explicitly states: “Ratio is absolutely fine and strong with the likes of Cruising in the Stellar Sea, but his performance goes up by that much more with his signature Light Cone, and it provides better quality of life than trying to maintain the passives of other Light Cone options.” Mobalytics confirms: “Dr. Ratio’s Signature Light Cone is not only the best Light Cone for himself, but it is also a quite flexible Light Cone that many follow-up attackers can utilize.”
Worrisome, Blissful
⭐⭐⭐⭐⭐ Topaz’s Signature — Strong FUA AltPremium Alternative: Topaz’s signature provides +30% FUA DMG, +18% CRIT Rate, and the Tame debuff after each FUA — Tame causes the entire team to deal +12% CRIT DMG per stack (up to 2 stacks = +24% team CRIT DMG). The Tame debuff counts as a third debuff on the target, solving the 3-debuff threshold requirement without needing a separate debuffer. Dbltap explicitly recommends Worrisome, Blissful as a top Dr. Ratio alternative, noting the FUA DMG bonus and Tame’s debuff contribution to his mechanic. The +18% CRIT Rate helps reach Dr. Ratio’s 70%+ CRIT Rate target without heavy substat investment. Strong if you own it from Topaz’s banner.
I Venture Forth to Hunt
⭐⭐⭐⭐⭐ Feixiao’s Signature — SPD-Scaling AltSPD-Scaling Premium: Feixiao’s signature provides +18–30% CRIT Rate (S1: +18%) and scales Skill + Basic ATK DMG and Ultimate CRIT DMG based on SPD above 100 — each 10 SPD above 100 adds +6% Skill/Basic DMG and +12% Ultimate CRIT DMG (up to 6 stacks). Prydwen’s calculations note: “Calcs contain some reallocation of ATK%, CRIT RATE, and CRIT DMG% to SPD in order to achieve 4-6 stacks of the bonus. With better relics and teams that grant more Speed this Cone’s performance will improve comparatively.” Competitive with Baptism if you can achieve 160+ SPD. Flexible — also excellent on Feixiao herself if you have both characters built.
Cruising in the Stellar Sea
⭐⭐⭐⭐⭐ Best Accessible Non-SignatureBest “I don’t have the signature” option: Provides +16% CRIT Rate (important for reaching 70%+ target) and +16% CRIT Rate against enemies ≤50% HP (total +32% CRIT Rate in boss-fight second halves). When defeating an enemy, +40% ATK for 2 turns. Multiple sources (Dexerto, dbltap, GameRant) list Cruising as the recommended accessible alternative. Prydwen confirms: “Ratio is absolutely fine and strong with the likes of Cruising in the Stellar Sea.” The CRIT Rate contribution is particularly valued since Dr. Ratio needs both CRIT Rate and CRIT DMG from relics — Cruising’s +16% base CRIT Rate significantly reduces CRIT Rate pressure from substats, freeing rolls for CRIT DMG. Available from Standard Banner warp pool.
Sleep Like the Dead
⭐⭐⭐⭐⭐ Standard CRIT DMG OptionCRIT DMG Stat Stick: Provides a large +30–50% CRIT DMG boost and +36–60% CRIT DMG when the wearer does not deal CRIT for 3 turns (conditional). The base CRIT DMG is strong — and since Dr. Ratio crits frequently (with good CRIT Rate + guaranteed FUAs at 3 debuffs), the conditional portion is less reliable but the base flat CRIT DMG is always active. Dexerto lists it as a viable alternative alongside Cruising. Use when you have this LC from the standard banner and don’t have Cruising or premium alternatives — the CRIT DMG is significant.
In the Night
⭐⭐⭐⭐⭐ SPD-Scaling Standard 5★SPD-Build Option: Provides +18% CRIT Rate and scales Skill + Basic ATK DMG and FUA CRIT DMG based on SPD — +6% Skill/Basic DMG and +12% FUA CRIT DMG per 10 SPD above 100 (up to 6 stacks). At 160+ SPD, In the Night adds meaningful FUA CRIT DMG and Skill DMG amplification. Prydwen includes it in calculations with SPD reallocation. Note: requires SPD investment to fully activate, which reduces ATK% from boots — a trade-off worth considering only if you’re building a high-SPD Dr. Ratio variant. Use Cruising or Sleep Like the Dead for simpler builds without SPD reallocation.
Baptism of Pure Thought is Dr. Ratio’s most significant individual upgrade — Prydwen notes his performance “goes up by that much more with his signature.” However, Dr. Ratio is A-Tier; pulling his signature specifically for a rerun A-Tier DPS is a high Stellar Jade cost for the performance improvement. Cruising in the Stellar Sea + good relics makes Dr. Ratio fully capable of all endgame content. Pull the signature if you are a dedicated Dr. Ratio main who wants his ceiling and enjoys the character; skip if Stellar Jade is limited and higher-tier characters are on the horizon. Mobalytics notes the LC is “flexible” on multiple Hunt FUA characters — making it a better investment if you also run Feixiao or Moze.
Best Relic Sets
4-Piece Cavity Relics
Why It’s #1: Dr. Ratio’s FUAs are his primary damage source — the unconditional +20% FUA DMG from the 2-piece applies to every FUA proc throughout the fight. The 4-piece ATK stacking from FUA hits begins immediately from the first FUA and builds to maximum (+48% ATK) within the first couple of Skill/FUA cycles, especially in FUA-dense teams with Robin’s Concerto or Topaz’s Numby providing additional FUAs. At high ATK, the combined +20% FUA DMG + +48% ATK amplification is the highest DPS Relic set for Dr. Ratio in standard FUA compositions. GameRant: “The Ashblazing Grand Duke 4-piece set is ideal.” Multiple sources including dbltap and hsrleaks confirm Ashblazing as the primary recommendation.
When to Use: Mobalytics highlights Pioneer Diver as strong for Dr. Ratio specifically in teams where maintaining 3+ debuffs is consistent and reliable. At 3 debuffs, Pioneer’s +20% CRIT DMG (or +40% CRIT DMG for 1 turn after debuff application) combines with Baptism of Pure Thought’s debuff-scaling CRIT DMG for compounding critical damage stacks. In Jiaoqiu + Dr. Ratio teams (where Jiaoqiu consistently stacks 4–5 debuffs), Pioneer’s full bonus is perpetually active — making it competitive with or superior to Ashblazing in high-debuff compositions. Use in Silver Wolf or Jiaoqiu teams where debuff count is reliably 3+; use Ashblazing in FUA-heavy compositions where debuff count may be exactly 3 (not higher).
When to Use: GameRant notes: “As an Imaginary unit, Dr. Ratio can benefit from the 4pc of Wastelander of Banditry Desert.” The +10% CRIT Rate at 3 debuffs (virtually always active in endgame Dr. Ratio teams) is free CRIT Rate without substat cost. In teams with Silver Wolf or Welt who can inflict Imprisonment, the additional +20% CRIT DMG is a further compound bonus. The Imaginary DMG +10% from 2-piece is less universally applicable than Ashblazing’s FUA DMG% but works in all content. Best against Imaginary-weak enemies where the element bonus multiplies. GameRant recommends running it specifically when Welt is paired with Dr. Ratio for the Imprisonment CRIT DMG bonus.
When to Use: GameRant: “combining 2pc of Ashblazing Grand Duke + 2pc of Wastelander of Banditry Desert since they easily grant Dr. Ratio 10% Imaginary DMG and 20% Follow-up attack DMG without any requirements.” When fighting non-Imaginary-weak enemies, this hybrid drops to approximately equal performance with pure Ashblazing 4-piece (since the +10% Imaginary DMG doesn’t apply cleanly to all content). Best in content specifically tagged with Imaginary Weakness, where both 2-piece bonuses are active simultaneously. Otherwise, pure Ashblazing 4-piece edges out the hybrid for universal play.
Planar Ornaments
Why It’s #1: In FUA-heavy teams (Dr. Ratio + Topaz + Robin + Aventurine), FUAs accumulate extremely quickly — Topaz’s Numby, Aventurine’s FUA, Robin’s Concerto FUAs, and Dr. Ratio’s own FUAs all contribute Merit stacks. Reaching 5 stacks (and the +25% CRIT DMG bonus) typically happens within the first 2–3 turns of a fight. Combined with the base +25% FUA DMG at 5 stacks, Duran provides +50% total FUA amplification (25% DMG + 25% CRIT DMG) to every FUA Dr. Ratio fires — an enormous single ornament contribution. Dbltap: “Duran, Dynasty of Running Wolves” is the recommended ornament alongside Inert Salsotto.
When to Use: In teams without high FUA density (fewer FUAs from allies = slower Duran stack accumulation), Inert Salsotto’s unconditional +15% FUA DMG (at 50%+ CRIT Rate, easily achievable) is more reliable than Duran’s team-dependent Merit stacking. GameRant and dbltap both list it as a strong alternative: “2pc of Inert Salsotto are the best Relics for Dr. Ratio since it buffs his Crit Rate, Ultimate, and follow-up attacks.” Use Duran in FUA team compositions with many allied FUAs; use Inert Salsotto in teams where allied FUA frequency is lower (e.g., Silver Wolf + Pela + Dr. Ratio without dedicated FUA sub-DPS).
When to Use: In high-SPD Dr. Ratio builds (160+ SPD) using In the Night or I Venture Forth to Hunt LCs that scale with SPD, Glamoth’s ATK stacking at the 160 threshold adds meaningful offensive power. GameRant notes Glamoth as a “decent option” in SPD-focused builds. Not recommended for standard builds that use ATK% boots — Glamoth’s value is only realised at 160+ SPD, which requires significant speed investment from substats and forgoing ATK% boots.
Stat Priorities
Main Stats
Target Stats
Substat Priority
- CRIT Rate — Must reach 70%+ for reliable FUA crits. Dbltap recommends “CRIT Rate between 65-70%” as the target range. Dr. Ratio fires many individual FUA hits — each one needs to crit consistently. Every CRIT Rate substat roll until 70%+ is secured is the highest-value investment. CRIT Rate from the body piece handles most of this; substats cover the gap.
- CRIT DMG — Once CRIT Rate is secured, CRIT DMG compounds the signature LC’s debuff-scaling bonus (+56% total CRIT DMG at 3 debuffs with Baptism), Pioneer’s CRIT DMG bonus, and Duran’s +25% CRIT DMG at 5 stacks. Each CRIT DMG substat roll adds to a multiplier that scales with every FUA proc. Stack aggressively after 70% CRIT Rate is achieved.
- ATK% — All Dr. Ratio damage sources scale with ATK. Ashblazing’s +48% ATK also compounds off the base ATK from substats. Third priority after CRIT stats are at comfortable levels — ATK% from rope handles most of the ATK budget, substats extend it further.
- SPD — More actions per cycle = more Skill uses = more FUAs. SPD boots handle primary SPD investment; SPD substats supplement toward 134+ baseline or 160+ for SPD-scaling builds. Fourth priority — invest after CRIT stats and ATK are at comfortable levels.
Trace Priority
- Talent — “Cogito, Ergo Sum”
The FUA source — every Talent level increases the FUA damage multiplier. Since the Talent fires on nearly every Skill use (guaranteed at 3 debuffs), higher Talent levels improve the primary damage dealer of every fight. Max first without exception — this is the majority of Dr. Ratio’s total damage output and the trace that scales most directly with investment. - Skill — “Intellectual Midwifery”
The Skill’s Imaginary DMG is meaningful (and the direct trigger for the Talent FUA). Higher Skill levels increase the initial Imaginary hit before the FUA fires. Second priority — max alongside Talent as complementary offensive traces. Together they constitute the Skill → FUA damage cycle. - Ultimate — “Syllogistic Paradox”
Higher Ultimate levels increase the Wiseman’s Folly bonus DMG triggered when FUA hits the debuffed target. The Ultimate itself also deals Imaginary DMG. Third priority — upgrade after Talent and Skill for the Wiseman’s Folly damage component. - Basic Attack — “Mind is Might”
Lowest priority. Basic Attack is only used for SP recovery in SP-tight rotations — never as a damage tool. Leave at a lower level until all other traces are invested, then cap when resources allow.
A4 — “Ratio’s Enlightenment”: When the FUA hits a target with 5+ debuffs, FUA DMG multiplier increases by an additional percentage. Unlock as soon as possible — the 5-debuff bonus is passively active whenever the team achieves that count. Combined with Silver Wolf + Topaz or Jiaoqiu compositions, this bonus fires consistently in endgame rotations.
A6 — “Ratio’s Imminence”: Dr. Ratio deals additional Imaginary DMG when enemies are attacked while within certain mechanics (the A6 trace increases Imaginary Weakness bonus DMG and Break-adjacent effects). The A6 benefit compounds in Imaginary Weakness content — unlock early for fights against Imaginary-weak enemies. Provides a consistent passive damage increase that requires no player action.
A2 — “Ratio’s Theorem”: Improves the base FUA chance or adds a small energy recovery mechanic (contextual — ensure this is unlocked for the quality-of-life benefit to Ultimate cycling and FUA trigger reliability). Upgrade third among bonus traces after A4 and A6.
Best Team Compositions
🎭 Classic FUA Core — Robin + Topaz
The classic Dr. Ratio FUA composition — identified by Prydwen as his standard premium team and used by the majority of players in current MoC. Each unit fills a precise role:
Topaz’s role: Applies Proof of Debt (debuff) to the primary target, enabling Dr. Ratio’s Skill FUA at 60% base chance before other debuffs. With E1 (Proof of Debt applies 2 debuffs) or Worrisome, Blissful LC (Tame = 3rd debuff), Topaz alone satisfies the 3-debuff threshold. Prydwen: “With either E1 or her Light Cone, or with both, she can completely fill the debuff needs for him.” Topaz’s Numby also triggers when the Proof of Debt target is hit by Dr. Ratio’s FUA — advancing Numby forward for additional FUA procs. Every Numby attack contributes Duran Merit stacks.
Robin’s role: Concerto advances all allies by 100% and provides flat ATK buff to every ally during Concerto — amplifying Dr. Ratio’s FUA ATK base. Robin’s A4 provides +25% FUA CRIT DMG to all allies — stacking with Dr. Ratio’s Baptism CRIT DMG, Pioneer’s CRIT DMG, and Duran’s CRIT DMG simultaneously. Robin is the perfect buffer for any FUA-heavy team.
Aventurine’s role: Shields without SP cost, his own FUA procs to build Duran Merit stacks faster, and Imaginary Weakness resistance reduction. Prydwen confirms this is the #1 Dr. Ratio team in the current meta.
🎭 Silver Wolf + Moze — 5-Debuff Maximum
Prydwen explicitly highlights: “Moze — Dr. Ratio relies on enemies being debuffed at least 3 times (but ideally 5). Each of these characters solve each other’s problems perfectly.” Silver Wolf provides DEF Reduction + Element Implant + random debuff (3 debuffs), while Moze adds Prey mark + A6 FUA Vulnerability (2 more). At 5 debuffs, Dr. Ratio’s A4 bonus fires on every FUA and Baptism’s CRIT DMG scaling reaches maximum — the highest personal DPS ceiling available.
Silver Wolf’s element implant: Implanting Imaginary Weakness onto targets that don’t have it ensures Dr. Ratio’s Imaginary DMG always benefits from Weakness exploitation. In MoC and AS fights against non-Imaginary-weak enemies, Silver Wolf’s implant is the single most significant team contribution — transforming every hit into Weakness-exploiting Imaginary DMG.
Moze’s dual role: Provides 2 debuffs (reaching 5 with Silver Wolf), contributes significant FUA sub-DPS from the Departed state, and his Prey’s frequent FUA attack cycle benefits from Dr. Ratio’s FUA procs activating Moze’s Charge depletion simultaneously. A natural feedback loop between the two characters’ FUA mechanics.
🎭 Jiaoqiu + Robin — Fire Vulnerability Core
Prydwen explicitly lists Jiaoqiu as a top Dr. Ratio partner: “Jiaoqiu — Dr. Ratio relies on his team to apply 3-5 debuffs to bring his kit fully online.” Jiaoqiu’s Ashen Roast stacks (each counting as a debuff, up to 5) + his A6 FUA Vulnerability (+25% FUA DMG taken) synergise deeply with Dr. Ratio’s debuff-scaling mechanics:
Jiaoqiu’s 5-stack contribution: At 5 Ashen Roast stacks, Dr. Ratio has 5 debuffs active — triggering A4’s bonus FUA DMG and Baptism’s full +24% CRIT DMG (3-debuff cap). Jiaoqiu alone can maintain 4–5 debuffs without any other debuffer needed.
Zone synergy: Jiaoqiu’s Zone applies +15% Ultimate DMG Vulnerability — Dr. Ratio’s Wiseman’s Folly-enhanced Ultimate benefits directly from this. The Zone also passively re-applies Ashen Roast on every enemy action, maintaining 4–5 stacks throughout the fight and sustaining Dr. Ratio’s CRIT DMG bonuses from Baptism.
Robin’s role: In the 4th slot, Robin provides the standard FUA team bonuses — Concerto advance, ATK buff, and +25% FUA CRIT DMG — without needing to contribute debuffs (Jiaoqiu handles the debuff requirement entirely).
🎭 F2P Accessible — Pela + Moze
The F2P-accessible Dr. Ratio team. Pela — a free 4-star — provides DEF Reduction via her Ultimate (1 debuff) and, with Resolution Shines As Pearls of Sweat LC, applies an additional debuff from each Basic Attack. Moze contributes 2 debuffs (Prey mark + A6 FUA Vulnerability). Combined: Pela DEF shred + Pela Resolution debuff + Moze Prey + Moze A6 = 3–4 debuffs consistently — meeting and exceeding Dr. Ratio’s 3-debuff guarantee threshold.
Gallagher as sustain: Free from the Standard Banner and SP-positive — his Basic Attack + Zone combination keeps the team’s SP available for Dr. Ratio’s Skill-heavy rotation. The Gallagher + Moze + Pela combination is all accessible without rate-up banner pulls.
This team can clear Memory of Chaos 8–11 consistently and improves further as relics are upgraded. The path from this F2P team to the premium team is clear: replace Pela with Silver Wolf or Robin when available, replace Gallagher with Aventurine when possible, keep Moze permanently.
Eidolons Guide
| Eidolon | Effect | Priority |
|---|---|---|
| E0 | Complete, fully functional A-Tier single-target FUA DPS. 40% + 20% per debuff FUA chance (guaranteed at 3 debuffs), Wiseman’s Folly bonus hits from Ultimate, A4 5-debuff bonus, A6 passive amplification. Dr. Ratio at E0 with Baptism of Pure Thought and good relics clears all current endgame content. All tier ratings are based on E0 performance. No eidolons are required for his A-Tier contribution. | Complete A-Tier |
| E1 | “Pride Above All” — When FUA is triggered, the DMG multiplier of the FUA increases by a percentage.
A direct FUA damage multiplier increase — every E1 FUA proc deals more damage than E0 would. Since the FUA fires on essentially every Skill cast at 3+ debuffs, this multiplier improvement applies continuously throughout fights. A quality multiplier upgrade; not dramatically transformative but consistent. |
FUA Multiplier Boost |
| E2 | “Justice For All” — When Dr. Ratio uses a FUA, additionally reduces the target’s DEF by a percentage for a limited duration.
DEF reduction from FUA significantly amplifies all subsequent hits — Dr. Ratio’s Skill DMG, future FUAs, Wiseman’s Folly proc hits, and his teammates all benefit from the target’s reduced DEF. The self-applying DEF shred also means Dr. Ratio no longer needs a dedicated DEF-reduction support (Pela, Silver Wolf) to reach full DEF shred effectiveness — freeing a team slot for a pure buffer. A meaningful utility eidolon. |
Team DEF Shred Utility |
| E4 | “Wisdom Beyond All” — Dr. Ratio’s FUAs now always deal a fixed number of additional Imaginary hits alongside the main FUA.
Additional Imaginary hits added to every FUA proc — in effect, each FUA action deals more total Imaginary damage without requiring any additional mechanic. The stacked hits also contribute to Ashblazing’s ATK stacking (more FUA hits = more ATK stack procs) and Duran’s Merit stacking. A meaningful upgrade for players who have accumulated E4 naturally. |
Additional FUA Hits |
| E6 | “Genius Above All” — Dr. Ratio’s FUA CRIT DMG increases significantly, and debuffs on the target beyond the base threshold provide additional FUA enhancements.
E6 Dr. Ratio is a substantial personal DPS amplifier — the FUA CRIT DMG increase compounds with Baptism’s debuff-scaling CRIT DMG and Duran’s FUA CRIT DMG for an extraordinary ceiling in maximum-debuff scenarios. However, as Prydwen notes, “his glory days have passed” — E6 investment on an A-Tier character whose main archetype (FUA) has a higher-tier alternative (Feixiao) is a very deep commitment. Only pursue E6 as a dedicated Dr. Ratio main. |
Dedicated Main Only |
Dr. Ratio is available on the Standard Banner (always obtainable via Stellar Jade, Departure Warp, and Standard Banner pulls). Over time, players accumulate eidolons naturally from standard pulls and event rewards. E1 and E2 improve his FUA multiplier and add self-applied DEF shred — both are meaningful quality-of-life and damage upgrades that arrive organically. E4 and E6 require targeted investment; with his A-Tier status, prioritise building his relics and LC before pursuing higher eidolons.
Should You Build Dr. Ratio?
✅ Build If:
- You received him for free from a past Trailblaze event or have him from the Standard Banner — he’s accessible and a worthwhile investment of relic resources. Free A-Tier DPS is always worth building if you need a single-target boss killer.
- You want an Imaginary DPS and don’t have Feixiao — Dr. Ratio is the best accessible Imaginary FUA DPS available outside of Feixiao. His debuff-scaling kit is well-understood and consistent in boss content.
- You can build 3+ debuffs consistently with your existing roster — if you already have Silver Wolf, Topaz, Jiaoqiu, or Moze, Dr. Ratio’s debuff requirement is trivially met and his FUA output is strong.
- You enjoy the debuff-scaling intellectual theme and the gameplay loop of building debuff stacks for guaranteed FUAs — his kit has a clear, rewarding relationship between team debuff investment and personal damage output.
- You want a reliable single-target boss killer for MoC and AS — his single-target focus is genuinely excellent in the content modes that dominate HSR endgame (MoC boss fights, AS single-target encounters).
⚠️ Consider Deprioritising If:
- You don’t have and can’t maintain 3 debuffs — below 3 debuffs, Dr. Ratio’s FUA is unreliable and his damage drops noticeably. Don’t build Dr. Ratio without a plan for debuff sourcing.
- You plan to pull Feixiao — Feixiao does everything Dr. Ratio does and does it better in the current meta. Prydwen explicitly recommends checking Feixiao first for FUA players. Save resources for Feixiao if she’s on your radar.
- Your endgame priority is Pure Fiction AoE clearing — Dr. Ratio has essentially no AoE and cannot contribute meaningfully to wave-clearing content. Invest in AoE DPS like Jade, The Herta, or Himeko for Pure Fiction.
- You need to pull Stellar Jade for a DPS rerun — Dr. Ratio is an A-Tier on the Standard Banner. Reruns of higher-tier limited DPS characters (Acheron, Phainon) represent a better meta return on Stellar Jade investment.
Final Verdict: Dr. Ratio is a well-designed, thoughtful character whose kit has aged into a comfortable and honest A-Tier position. He was genuinely the best FUA DPS in the game at release, and his debuff-scaling mechanics are still sound — but Feixiao and the expanded FUA roster have created stiffer competition. Build Dr. Ratio if you have him, enjoy the Intelligentsia Guild’s masked debuff philosopher, and have a team that can meet his 3-debuff requirement. Give him Baptism of Pure Thought if you pull it on rerun, max his Talent, and he will reward you with consistent, punishing single-target damage throughout the entire current patch. His glory days may have passed — but the Mundanite still performs.
Dr. Ratio vs Other Single-Target FUA DPS
vs Feixiao (S+ Tier): Feixiao is the superior FUA DPS by every metric — higher damage ceiling, does not require debuffs to function optimally, generates Flying Aureus from all allies’ FUAs rather than being debuff-gated, and has stronger team scaling. Prydwen: “She can do what Dr. Ratio does, but better.” Feixiao is the priority pull if you want the premier FUA DPS; Dr. Ratio is the accessible alternative while Feixiao is unavailable.
vs Yunli / Clara (Counter FUA): Yunli and Clara operate as counter-based FUA DPS requiring enemies to attack them — a different archetype that doesn’t compete with Dr. Ratio’s debuff-gated archetype. In content without counters, Yunli and Clara are less effective; in counter-favorable content, they can edge Dr. Ratio. They are complementary options for different team structures.
vs March 7th (Hunt form): March 7th’s Hunt Swordmaster form is the F2P FUA DPS option — providing good accessible damage without being debuff-gated. She doesn’t approach Dr. Ratio’s ceiling with proper debuff teams but is easier to build and doesn’t require specific 5-star supports to function. Use March for F2P teams; Dr. Ratio for dedicated investment.