Topaz & Numby — Honkai Star Rail Character Guide

Overview

FUA support who applies Proof of Debt for a 50% follow-up damage multiplier and summons Numby as a persistent attacking unit. Peak value in dedicated FUA teams with Feixiao or Dr. Ratio; struggles in AoE content and without follow-up teammates.

FUA hybrid support/sub-DPS who summons Numby (80 SPD independent entity) and applies Proof of Debt for a 50% separate follow-up damage multiplier on the marked enemy. Core gameplay loop: apply Proof of Debt via Skill, then generate as many ally follow-up attacks as possible to advance Numby's action forward by 50% per FUA hit. Ultimate buffs Numby into Windfall Bonanza! state for 2 enhanced attacks with +150% DMG multiplier and +25% CRIT DMG, while also expanding the Advance Forward trigger to include Basic ATKs, Skills, and Ultimates.

Key Mechanics

• Proof of Debt's 50% FUA DMG increase is a separate multiplier applied after other damage calculations, making it exceptionally potent — significantly more than a simple 50% additive DMG% buff.
• Numby's action frequency scales directly with team FUA density. Each ally follow-up attack on the Proof of Debt target advances Numby by 50%, creating a feedback loop — more FUAs mean more Numby attacks, which mean more damage and Energy.
• SP flexible: both Basic ATK (via A2) and Skill count as follow-ups and advance Numby equally. The choice between them is purely an SP/damage tradeoff, not a Numby advancement tradeoff.
• Exclusively single-target — Proof of Debt can only mark one enemy, and Numby only attacks the marked target. Effectiveness drops sharply in AoE content like Pure Fiction.
• CRIT Rate is the primary stat bottleneck because consistent crits keep Numby cycling. Without signature LC, reaching 80%+ CRIT Rate requires heavy substat investment.

Best Topaz & Numby Teams

Follow-Up Attack Hypercarry

Topaz's core role as a FUA support alongside a premier FUA DPS. Proof of Debt's 50% follow-up damage increase is a separate multiplier applied after all other calculations, making it exceptionally potent — a single debuff that amplifies every follow-up from every ally throughout the fight. Pairs with Robin and Aventurine for maximum follow-up density and damage output. Feixiao and Dr. Ratio are the best-in-slot DPS slots, but Yunli and Clara are functional alternatives.

• S-tier: Topaz & Numby, Feixiao, Robin, Aventurine
• S-tier: Topaz & Numby, Dr. Ratio, Robin, Aventurine
• A-tier: Topaz & Numby, Feixiao, Sunday, Huohuo
• A-tier: Topaz & Numby, Dr. Ratio, Tribbie, Aventurine

Follow-Up Dual Carry

Topaz acts as a secondary DPS alongside another FUA damage dealer, sharing amplification and a single sustain slot. Proof of Debt buffs both DPS simultaneously as long as both are hitting the same target, making this composition naturally efficient. Best used when two strong FUA DPS characters are available and the second amplifier slot is contested.

• S-tier: Topaz & Numby, Feixiao, Robin, Aventurine
• A-tier: Topaz & Numby, Dr. Ratio, Robin, Aventurine

Best Topaz & Numby Teammates

DPS Partners: Feixiao (S), Dr. Ratio (S), Yunli (A), Ashveil (A), Clara (B), Jing Yuan (B)

Amplifiers: Robin (S), Tribbie (S), Sunday (A), Ruan Mei (B), Silver Wolf (B), Pela (B)

Sustains: Aventurine (S), Huohuo (A), Dan Heng • Permansor Terrae (A), Fu Xuan (B), Gallagher (B), Lynx (C)

Topaz & Numby Investment Priority

1. E1 — Adds +25% CRIT DMG per stack (up to 2 stacks) to all FUA attacks on Proof of Debt target — a team-wide multiplicative buff. Primary eidolon target if chasing copies.
2. LC S1 — Signature provides CRIT Rate, 50% FUA DMG boost, and Tame debuff adding team-wide CRIT DMG. Best pulled after E0 is functional.
3. E6 — Extra Numby attack during Windfall Bonanza plus 10% Fire RES PEN — next meaningful stop after signature for dedicated Topaz investment.

Topaz & Numby Relics and Stat Targets

Recommended: The Ashblazing Grand Duke with Duran, Dynasty of Running Wolves

Stat targets: SPD 134, CRIT Rate 70%+, CRIT DMG 140%+, ATK 2500+

Main stats: Body: CRIT Rate > CRIT DMG · Feet: SPD > ATK% · Sphere: Fire DMG > ATK% · Rope: ATK%

Best Topaz & Numby Light Cones

• Worrisome, Blissful (Best in Slot): BiS signature providing CRIT Rate and 50% FUA DMG boost. Tame debuff stacks up to 2 times and increases CRIT DMG dealt by all allies who hit the target by 20% per stack at S1 — a second team-wide damage amplifier layering with Proof of Debt. The combination of personal stats and team buff is difficult to replicate.
• See You at the End: Best accessible 4-star option. Provides CRIT DMG and follow-up attack DMG — both stats Topaz uses directly through her Basic ATK (which counts as FUA via A2 trace) and Numby's attacks. At S5 competes with S1 5-star alternatives for personal damage.
• Cruising in the Stellar Sea: Standard 5-star alternative providing CRIT Rate (which Topaz needs for consistent FUA damage) and conditional ATK buff on kill. Strong in multi-wave content but loses ATK value in pure single-boss scenarios. No team support benefit unlike signature.
• Swordplay: F2P budget option with stacking DMG bonus (+16% per hit at S5, up to 5 stacks). Easy to ramp with Numby's frequent attacks in single-target fights. Stacks reset if Proof of Debt moves to a different enemy, so best in single-boss content. Only viable at S5.

Topaz & Numby FAQ

Who works best with Topaz & Numby in HSR?

Topaz & Numby's best team options include Feixiao, Robin, Aventurine. StarGuide rates teammates by role and composition fit so the recommendation reflects how the character is actually played.

What relics should Topaz & Numby use?

Topaz & Numby's recommended relic setup is The Ashblazing Grand Duke with Duran, Dynasty of Running Wolves, with stat targets around SPD 134, CRIT Rate 70%+, CRIT DMG 140%+.

What is the best light cone for Topaz & Numby?

Worrisome, Blissful is the top listed light cone for Topaz & Numby. BiS signature providing CRIT Rate and 50% FUA DMG boost. Tame debuff stacks up to 2 times and increases CRIT DMG dealt by all allies who hit the target by 20% per stack at S1 — a second team-wide damage amplifier layering with Proof of Debt. The combination of personal stats and team buff is difficult to replicate.

How should I invest in Topaz & Numby?

Topaz & Numby's first listed investment priority is E1. Adds +25% CRIT DMG per stack (up to 2 stacks) to all FUA attacks on Proof of Debt target — a team-wide multiplicative buff. Primary eidolon target if chasing copies.

Important Notes

• Exclusively single-target — effectiveness drops sharply in Pure Fiction where AoE damage determines score
• Proof of Debt randomly reassigns to a live enemy at the start of each turn if the marked target dies, which can be disruptive during multi-wave fights
• Personal damage contribution collapses without follow-up attack teammates to advance Numby frequently
• Requires 80%+ CRIT Rate for reliable Numby performance; CRIT Rate is harder to source without signature cone