TOPAZ & NUMBY
IPC Debt Collector • FuA Enabler
S TIER SUB-DPSTopaz & Numby is a 5-star Fire Hunt character duo who revolutionized Follow-Up Attack (FuA) teams in Honkai: Star Rail. Topaz applies “Proof of Debt” to enemies, increasing FuA damage they receive by 50% (at max level)—one of the strongest single-target debuffs in the game. Her partner Numby (the adorable Warp Trotter) acts independently with 80 base SPD and launches automatic FuA on debted enemies.
What makes this duo exceptional is the bidirectional synergy: Every ally FuA against Proof of Debt targets advances Numby’s action by 50%, while Numby’s constant attacks help charge ally Ultimates and trigger FuA-based effects. Topaz’s Ultimate puts Numby in “Windfall Bonanza!” state—increasing DMG multiplier by 150% and CRIT DMG by 25% for next 2 attacks. During Bonanza, even Basic ATKs/Skills/Ultimates advance Numby!
She’s the premier enabler for FuA DPS like Feixiao, Dr. Ratio, and Yunli. With E1 (Debtor state), she becomes even stronger—granting 50% CRIT DMG to all FuA against marked enemies. Rated S-tier for being THE best FuA support in the game!
Best Light Cones
Worrisome, Blissful
⭐⭐⭐⭐⭐ SignatureBest-in-Slot: Increases CRIT Rate by 18% and FuA CRIT DMG by 30%. After using FuA, inflicts “Tame” on target (stacks 2x). Allies hitting Tamed enemies gain 12% CRIT DMG per stack (24% total). Since Numby constantly launches FuA, this provides team-wide CRIT DMG amplification!
Cruising in the Stellar Sea
⭐⭐⭐⭐⭐ F2P BestExcellent Free Option: Herta Store Light Cone. Increases CRIT Rate by 8% and ATK by 20% when SPD ≥120. Topaz easily reaches this threshold. Performs 70-75% as well as signature—best F2P choice!
Swordplay
⭐⭐⭐⭐ Budget 4-StarAccessible Alternative: For each hit on same target, DMG increases by 8% (stacks 5x = 40% total). Numby hits the same Proof of Debt target repeatedly, quickly maxing stacks. Great budget option at S5!
Return to Darkness
⭐⭐⭐⭐ Battle PassPremium 4-Star: Increases CRIT Rate by 12% and provides additional CRIT Rate when SPD ≥100. Topaz always meets this condition. Solid option from Battle Pass.
Best Relic Sets
The Ashblazing Grand Duke (4-Piece) – BEST
2-Piece: Increases FuA DMG by 20%
4-Piece: When using FuA, increases ATK by 6% per hit (max 8 stacks = 48% ATK), lasting 3 turns. Removed on next FuA.
Perfect Synergy: Numby’s multi-hit attacks quickly stack to 48% ATK. The 20% FuA DMG amplifies both Topaz’s and Numby’s damage. BiS relic set!
Pioneer Diver of Dead Waters (4-Piece) – Debuff Build
2-Piece: Increases DMG to debuffed enemies by 12%
4-Piece: Increases CRIT Rate by 4% per debuff on enemy (max 12%). Dealing CRIT to debuffed enemies increases CRIT DMG by 8-12% per debuff (max 36%).
Debuff Teams: Excellent in teams with Dr. Ratio, Acheron, or Jiaoqiu. The CRIT DMG scaling is massive with multiple debuffers!
Planar Ornaments
Duran, Dynasty of Running Wolves – BEST
2-Piece: When ally uses FuA, wearer gains 1 stack (max 5). Each stack increases FuA DMG by 5% (25% total). At 5 stacks, additionally increases CRIT DMG by 25%.
FuA Team Essential: In proper FuA teams, reaches max stacks within 2-3 turns for 25% FuA DMG + 25% CRIT DMG. Undisputed best ornament!
Inert Salsotto – Alternative
2-Piece: Increases CRIT Rate by 8%. When CRIT Rate ≥50%, Ultimate and FuA DMG increase by 15%.
Solid Option: Easy CRIT Rate threshold with Topaz’s base stats. Both Numby and Topaz benefit from FuA DMG boost!
Optimal Stats
Body: CRIT Rate / CRIT DMG
Feet: ATK% / SPD
Sphere: Fire DMG%
Rope: ATK% / Energy Regen
ATK: 2800+
CRIT Rate: 70-85%
CRIT DMG: 140%+
SPD: 120-145
💰 Stats Priority
ATK is King! All of Numby’s damage scales with Topaz’s ATK. Target 2800+ ATK minimum. CRIT Balance: Aim for 1:2 ratio (70% CR : 140% CD). Signature cone provides 18% CR making this easier. SPD Notes: 120+ recommended but not critical—Numby has separate turn order. Sub-stats: CRIT Rate = CRIT DMG > ATK% > SPD > Break Effect.
Best Team Compositions
🔥 Premium FuA Core (Best Team)
The Ultimate FuA Team: This is THE premier Follow-Up Attack composition in the game. Feixiao’s constant FuAs rapidly advance Numby while Numby’s attacks advance Feixiao’s Flying Aureus generation. Robin provides team-wide action advance, 228+ ATK buff, and 25% CRIT DMG for all FuAs. Topaz’s 50% FuA DMG vulnerability marking amplifies Feixiao’s Ultimate damage by massive amounts. Aventurine contributes his own FuAs while providing shields and 10% CRIT DMG vulnerability. Every character triggers each other’s mechanics—creates unstoppable damage loop!
🎓 Dr. Ratio Intelligence
Debuff Synergy: Dr. Ratio launches FuA whenever hitting debuffed enemies (max 2 per ally action). Topaz’s Proof of Debt counts as debuff. Silver Wolf provides 3+ debuffs (weakness implant, DEF reduction, Bugs). Pela offers DEF shred and exposed vulnerability. With 3+ debuffs, Ratio gains 50% bonus FuA DMG from his A2 Trace. Aventurine adds sustain + debuff through his Ultimate. Excellent single-target annihilation team!
🌟 F2P Accessible
Budget Powerhouse: March Hunt (free) launches coordinated FuAs when Topaz attacks her “Shifu” target. Bidirectional synergy—March’s FuAs advance Numby, Numby’s attacks help March. Asta (free) provides ATK% and SPD buffs. Gallagher (free) offers healing and is SP-positive. Despite all-free supports, this team clears Memory of Chaos comfortably!
🎯 Team Building Tips
Core Principle: Topaz works EXCLUSIVELY with FuA-focused teams. Her 50% FuA DMG vulnerability is wasted on non-FuA DPS. Best Partners: Feixiao (perfect synergy) > Dr. Ratio (debuff synergy) > Yunli (counter-FuA) > Clara (counter-FuA). Support Priority: Robin (best FuA support) > Aventurine (FuA sustain) > March Hunt (F2P FuA) > Moze (4-star FuA).
Gameplay Guide
Proof of Debt System
• Skill applies Proof of Debt to one enemy (only one target can have it)
• Marked enemies receive 50% increased FuA damage (max level)
• If no enemy has Proof of Debt at ally turn start, random enemy gains it automatically
• When marked enemy dies, Proof of Debt transfers to another enemy
• This debuff is MULTIPLICATIVE with other damage bonuses—extremely powerful!
Numby Action Advance Mechanics
• Base SPD: 80 (acts independently from Topaz)
• Every ally FuA against Proof of Debt enemy = 50% action advance for Numby
• Two FuAs = 100% = Numby acts immediately!
• During Windfall Bonanza: Basic ATKs, Skills, Ultimates ALSO advance Numby by 50%
• This creates exponential action frequency in FuA teams
• Numby can attack 4-6 times per cycle in optimal teams!
Optimal Rotation
1. Use Technique before battle (regenerates 60 Energy for Topaz)
2. Topaz uses Skill on priority target (applies Proof of Debt + Numby attacks)
3. Allies launch FuAs → advances Numby
4. When Ultimate ready: Activate Windfall Bonanza state
5. Immediately use Skill → Enhanced Numby attack
6. Numby attacks again due to 100% action advance (2 enhanced attacks back-to-back!)
7. Basic ATK to conserve SP when Skill unnecessary
💡 Pro Tips
• Frontload Burst: Using Skill right after Ultimate triggers both enhanced Numby attacks immediately (100% action advance from two 50% advances). Massive burst but sacrifices sustained damage.
• A2 Trace Essential: Changes Topaz’s Basic ATK to FuA damage—enables her to trigger FuA-based effects!
• Numby’s Independence: Numby can attack even when Topaz is crowd-controlled. The Trotter perseveres!
Should You Pull Topaz & Numby?
✅ Absolutely Pull If:
• You have Feixiao (they’re literally made for each other!)
• You run Dr. Ratio and want to maximize his potential
• You’re building FuA-focused teams (she’s essential!)
• You have Robin and want THE premier FuA comp
• You love adorable Trotters (Numby is precious!)
⚠️ Skip If:
• You don’t run any FuA DPS units
• You focus on hypercarry, Break, or DoT teams
• You lack Robin (Topaz performs much better with her)
• You’re saving for upcoming limited DPS
🏆 Final Verdict
Topaz & Numby is an S-tier Sub-DPS and THE best FuA support in Honkai: Star Rail. Her 50% FuA DMG vulnerability is irreplaceable in Follow-Up Attack teams. She transforms Feixiao from strong to unstoppable, enables Dr. Ratio’s full potential, and creates bidirectional synergy loops that dramatically amplify team damage. While niche (only works with FuA teams), she’s MANDATORY within that archetype. If you run Feixiao or Ratio—pull Topaz immediately. She’s their best teammate!