Dr. Ratio
★★★★★

Dr. Ratio Build

Dr. Ratio is a 5★ Imaginary character on the Path of The Hunt in Honkai: Star Rail. Below are the character's stats, skills and Eidolons — plus a pity calculator if you plan to pull.

Released: 17/01/2024 · v1.6· Updated: 03/07/2026
Updated for version 4.3 · 02/07/2026
Calculate pity to pull this character →
Community usage · phase 4.3.2
Stats from 16,423 real player profiles (Memory of Chaos) · community data by LvlUrArti
Building Dr. Ratio — just follow the numbers
30-second summary

Worth pulling if you love a bursty single-target hunter and already own debuff-appliers. Skip if you lack debuff sources or mainly need wave-clear.

1
30-second build
In a hurry? This box is all you need — details below
BodyCRIT Rate / CRIT DMG FeetSPD (hoặc ATK%) SphereImaginary DMG RopeATK%

Sub-stat priority: CRIT DMG ≧ CRIT Rate > ATK% > SPD

2
Verdict & playstyle
How strong, worth pulling, how to play
Memory of Chaos 4/5
Pure Fiction 2/5
Apocalyptic Shadow 3.5/5
Should you pull Dr. Ratio?

Worth pulling if you love a bursty single-target hunter and already own debuff-appliers. Skip if you lack debuff sources or mainly need wave-clear.

Pros
  • Elite single-target and toughness-break damage
  • Excellent self-energy generation from follow-ups
  • Fully functional at E0, no eidolons required
Cons
  • Team must land 3+ debuffs to unlock his kit
  • Very weak in wave-clear content (Pure Fiction)
  • Picky about allies and partly power-crept by newer DPS
How to play

Each turn Skill the target that already has 3+ debuffs to trigger his follow-up, favoring an enemy with DEF shred. Hold Ultimate to open the Disputation buff before your big hits, then farm extra follow-ups from Topaz or allies.

3
Full build
Light cones, relics, stat targets — with reasons
Best Relics
BodyCRIT Rate / CRIT DMG
FeetSPD (hoặc ATK%)
SphereImaginary DMG
RopeATK%

Sub-stat priority: CRIT DMG ≧ CRIT Rate > ATK% > SPD

Stat targets

Targets: ~70-80% CRIT Rate on the sheet (100% in combat via cone/set), 180-200% CRIT DMG, 3000+ ATK, 134+ SPD. No EHR needed.

4
Teams
Best teammates to pair with
Best teams for Dr. Ratio

Standard: Topaz + Robin + Aventurine to max follow-ups. Debuff line: Jiaoqiu for durable debuffs + Robin.

Budget: Pela DEF shred + Tingyun + Gallagher.

Meta suggestions synthesized from global community consensus (Meta 2026-07). Figures come from game data — updated each patch.

5
Eidolons
How far to invest, which milestones matter

E0 (E1/E2 rất mạnh nếu dư nguyên liệu) — E0 is fully complete. E1 boosts follow-up damage, E2 is a strong Skill buff if you have spare pulls, and E6 is the real spike. None are needed.

E1
Pride Comes Before a Fall★★★★☆
The maximum stackable count for the Trace "Summation" increases by 4. When a battle begins, immediately obtains 4 stacks of Summation. Needs to unlock Summation first.
Raises the Summation stack cap by 4 and grants 4 stacks instantly at battle start, letting Dr. Ratio reach peak Summation value much earlier.
E2
The Divine Is in the Details★★★★☆
When his Talent's Follow-Up ATK hits a target, for every debuff the target has, deals Imaginary Additional DMG equal to 20% of Dr. Ratio's ATK. This effect can be triggered for a maximum of 4 time(s) during each Follow-Up ATK.
The Talent's Follow-Up ATK deals extra Imaginary DMG per debuff on the target, up to 4 times, meaningfully boosting overall damage.
E3
Know Thyself★★☆☆☆
Ultimate Lv. +2, up to a maximum of Lv. 15. Basic ATK Lv. +1, up to a maximum of Lv. 10.
Simply raises Ultimate and Basic ATK levels with no new effect, so its impact is fairly limited.
E4
Ignorance Is Blight★★☆☆☆
When triggering the Talent, additionally regenerates 15 Energy for Dr. Ratio.
Triggering the Talent additionally regenerates 15 Energy, a minor utility that slightly speeds up Ultimate uptime.
E5
Sic Itur Ad Astra★★☆☆☆
Skill Lv. +2, up to a maximum of Lv. 15. Talent Lv. +2, up to a maximum of Lv. 15.
Only raises Skill and Talent levels with no new effect, mainly giving a small boost to existing damage numbers.
E6
Vincit Omnia Veritas★★★★★
Additionally increases the trigger count for "Wiseman's Folly" by 1. The DMG dealt by the Talent's Follow-Up ATK increases by 50%.
Adds 1 more trigger of Wiseman's Folly and increases the Talent's Follow-Up ATK DMG by 50%, creating a huge overall damage spike.
6
Skills & Traces
What to level first — tap each skill for details
Skill Leveling Priority
Talent ★★★★★ The Talent's Follow-Up ATK (338% ATK) is Dr. Ratio's main damage source, so it must be maxed.
Skill ★★★★★ The Skill both deals direct damage and is the trigger condition for the Talent's Follow-Up ATK, making it as important as the Talent.
Ultimate ★★★★☆ The Ultimate applies Wiseman's Folly to let allies trigger extra Talent follow-ups, valuable but leveled after the core Skill/Talent.
Basic ATK ★★☆☆☆ Basic ATK is rarely relevant since the playstyle revolves around the Skill and follow-up attacks, so it stays lowest priority like most DPS.
Trace priority: A6 = A2 > A4 Eidolon priority: E6 > E2 > E1 > E4 > E3 = E5
Skills
Mind is Might
Mind is Might
Basic ATK Single Target Lv.10

Deals Imaginary DMG equal to 140% of Dr. Ratio's ATK to one designated enemy target.

Intellectual Midwifery
Intellectual Midwifery
Skill Single Target Lv.15

Deals Imaginary DMG equal to 188% of Dr. Ratio's ATK to one designated enemy target.

Syllogistic Paradox
Syllogistic Paradox
Ultimate Single Target Lv.15

Deals Imaginary DMG equal to 288% of Dr. Ratio's ATK to one designated enemy target and applies "Wiseman's Folly." When Dr. Ratio's teammates attack a target afflicted with "Wiseman's Folly," Dr. Ratio launches 1 instance of his Talent's Follow-Up ATK against this target. "Wiseman's Folly" can be triggered for up to 2 times and only affects the most recent target of Dr. Ratio's Ultimate. This trigger count resets after Dr. Ratio's Ultimate is used.

Cogito, Ergo Sum
Cogito, Ergo Sum
Talent Single Target Lv.15

When using his Skill, Dr. Ratio has a 40% fixed chance of launching a Follow-Up ATK against his target for 1 time, dealing Imaginary DMG equal to 338% of Dr. Ratio's ATK. For each debuff the target enemy has, the fixed chance of launching Follow-Up ATK increases by 20%. If the target enemy is defeated before the Follow-Up ATK triggers, the Follow-Up ATK will be directed at a single random enemy instead.

Attack
Attack

Attacks an enemy, and after entering combat, reduces their Toughness of the corresponding Type.

Mold of Idolatry
Mold of Idolatry
Technique Impair

After using Technique, creates a Special Dimension that Taunts nearby enemies, lasting for 10 second(s). After entering battle with enemies in this Special Dimension, there is a 100% base chance to reduce each single enemy target's SPD by 15% for 2 turn(s). Only 1 Dimension Effect created by allies can exist at the same time.

Major Traces
3 powerful passives (A2/A4/A6) — unlocked via Ascension
A2
Summation

When Dr. Ratio uses his Skill, for every debuff on the target, his CRIT Rate increases by 2.5% and CRIT DMG by 5%. This effect can stack up to 6 time(s).

A4
Inference

When Skill is used to attack an enemy target, there is a 100% base chance to reduce the attacked enemy target's Effect RES by 10% for 2 turn(s).

A6
Deduction

When dealing DMG to a target that has 3 or more debuff(s), for each debuff the target has, the DMG dealt by Dr. Ratio to this target increases by 10%, up to a maximum increase of 50%.

Trace Bonuses
Total stats gained from unlocking the full trace tree
+28%ATK
+12.5%DEF
+12%CRIT Rate
7
Stats & Materials
Base stats at Lv.80 and what to farm
Level 80 stats
HP
1,048
ATK
776
DEF
461
SPD
103
CRIT Rate
5%
CRIT DMG
50%
Ascension Materials
Total materials to max ascension — tap to see how to farm.
Material Planner →
8
Dr. Ratio FAQ
What is the best Light Cone for Dr. Ratio?

The best Light Cone for Dr. Ratio is Baptism of Pure Thought (top pick). See F2P options in the Light Cones section above.

Is Dr. Ratio worth pulling?

Worth pulling if you love a bursty single-target hunter and already own debuff-appliers. Skip if you lack debuff sources or mainly need wave-clear.

What is the best team for Dr. Ratio?

Standard: Topaz + Robin + Aventurine to max follow-ups. Debuff line: Jiaoqiu for durable debuffs + Robin. Budget: Pela DEF shred + Tingyun + Gallagher.

Matching Light Cones
Path of The Hunt — a Light Cone only gives its bonus to matching-Path characters.
Light Cones →
How to read this build page

Every character build page has these parts: recommended Light Cone/Relic sets and stat table, a Trace/skill leveling order, Eidolon milestones worth considering, and a reference SPD threshold. Read them in that order — gear tells you "what to use", Traces tell you "what to level first", Eidolon tells you "is it worth pulling dupes", SPD tells you "how fast you need to be to keep the rotation on time". The section below explains how to read each part and applies the same way to every character on the site — check the exact numbers in the table above this section, since community sources sometimes differ by a few points.

Why the Light Cone and Relic picks make sense

Most characters have a "signature" Light Cone built for their exact role, plus a few cheaper substitutes from the standard banner or easy-to-get 3-4★ cones. Missing the signature isn't a dead end — most characters keep most of their power with a well-matched substitute, typically losing somewhere between a few percent and roughly a fifth of total damage depending on the setup, per most public comparisons.

  • Relic sets (2pc+2pc or 4pc) are picked for the set effect that fits that character's role (single-target DPS, AoE, shield/healing support, Break damage, and so on).
  • Main stats per slot (Body/Feet/Sphere/Rope) and substats follow a priority that changes by role: DPS roles usually chase CRIT Rate/CRIT DMG before ATK%; Break-focused roles prioritize Break Effect; support/healing roles often value Effect Hit/RES or Outgoing Healing over pure CRIT.

These weights differ per character and can shift slightly between ranking sources — follow the exact priority table above rather than applying one formula to every role.

Trace/skill leveling order by role (a general guideline, not a fixed rule)

There's no single order that's correct for every character, and community sources sometimes disagree depending on the team the character is used in — but the general pattern by role is:

  • DPS: level whichever skill (Skill or Ultimate) carries most of the damage for that character first, with Basic ATK usually last if it isn't the main damage source.
  • Support/Buffer: prioritize Traces that boost buff strength or the skill that applies the effect over Basic ATK, since this role's value comes from lifting the team rather than personal damage.
  • Healer/Shielder: prioritize the main healing or shield skill first, since that is the reason the team runs this character.
  • Break/CC: prioritize whichever skill contributes the most Toughness Damage, since the Break/Weakness Break window is where the team dumps damage.

Major Traces unlock at fixed ascension levels in-game, not by choice — but which one to level first (when resources are limited) should follow the role priority above. Since the exact order can differ between ranking sources, check the specific recommendation in the table above for this character.

Eidolons: how far E0 gets you, and which milestone is worth considering

General rule: most characters at E0 (no duplicates) already handle most content, even 5-star characters. Eidolons are a duplicate-fueled upgrade system — higher levels cost more resources for a smaller power gain, and the actual gain varies a lot per character (some barely change role at E0, others shift how they're played at a specific level). The milestones most often cited by the community tend to sit at E1, E2, or E6 depending on the character — but none of these are required to clear the game's content. Check the Eidolon section in the table above for this character's specific milestone and gain; if sources disagree on how to rate a milestone, trust the in-game effect description over a pre-set percentage number.

How to think about SPD breakpoints

SPD (Speed) controls how often a character acts in the turn order — higher SPD means denser actions, and for some roles (especially support/healing that need to buff or heal before the team gets hit) hitting the right SPD "breakpoint" matters more than the raw SPD number. Values like 101 or 134 SPD are often cited as community-common breakpoints (letting a character act again before or after a specific point in certain team setups) — this is crowd-verified action-gauge math, not an official fixed number the game states for every situation. The right breakpoint also depends on the team and allies' SPD, so treat the SPD suggestion in the table above as a starting point to adjust from, not a mandatory target.

Where to dig deeper

This section only teaches you how to read the page — for deeper comparisons, use the dedicated tools:

  • Tier list to see where this character stands against the full roster.
  • Teams for full in-game comps with rotation order.
  • Relic score to check how your current gear scores against the benchmark.
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