Dr. Ratio 
The Hunt Member of the Intelligentsia Guild. Eccentric temperament, sharp-tongued but with an elegant demeanor. The face under the strange alabaster head sculpture is apparently unexpectedly handsome.
HP
ATK
DEF
SPEEDImaginary Dps Build
Best Light Cone
Dr. Ratio Best Stats
Dr. Ratio Best Substats
Dr. Ratio Best Relics
Dr. Ratio Best Ornaments
Duran, Dynasty of Running Wolves
Inert Salsotto
Izumo Gensei and Takama Divine Realm
Dr. Ratio Best Teams
Hypercarry (F2P)
This free-to-play Hypercarry setup runs Dr. Ratio as the Main DPS. March 7th (Imaginary) provides SPD and CRIT DMG buffs and extra damage, while Asta buffs Dr. Ratio's SPD and can apply Burn to help trigger Follow-up attacks. Natasha provides team sustain.
Follow-up Buffer + Debuffer (Cipher/Topaz)
Core idea: stack a buffer and a debuffer to maximize Dr. Ratio's Follow-up Attacks. Cipher provides extra damage while Robin buffs Follow-up DMG (works especially well with Aventurine sustain). Topaz and Cipher both synergize with Dr. Ratio — Topaz boosts Follow-up damage, Cipher adds damage. If you lack Aventurine, use heavy debuffers like Silver Wolf to maintain Follow-up uptime.
Silver Wolf Debuff + Shielder
Use this comp when the enemy is weak to Quantum but not Imaginary. Silver Wolf is essential here to implant an Imaginary Weakness; if the enemy is already weak to Imaginary, replace her with another debuffer. Aventurine provides shielding/sustain to keep the carry safe.
Skills
Deals Imaginary DMG equal to #1[i]% of Dr. Ratio's ATK to one designated enemy target.
Deals Imaginary DMG equal to #1[i]% of Dr. Ratio's ATK to one designated enemy target.
Deals Imaginary DMG equal to #1[i]% 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[i] times and only affects the most recent target of Dr. Ratio's Ultimate. This trigger count resets after Dr. Ratio's Ultimate is used.
Unleashes an extra attack on the target. This effect is triggered automatically when requirements are met.
When using his Skill, Dr. Ratio has a #2[i]% fixed chance of launching a Follow-Up ATK against his target for 1 time, dealing Imaginary DMG equal to #1[i]% of Dr. Ratio's ATK. For each debuff the target enemy has, the fixed chance of launching Follow-Up ATK increases by #3[i]%. 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.
Fixed chance will not be affected by any factor.
Unleashes an extra attack on the target. This effect is triggered automatically when requirements are met.
After using Technique, creates a Special Dimension that Taunts nearby enemies, lasting for #1[i] second(s). After entering battle with enemies in this Special Dimension, there is a #2[i]% base chance to reduce each single enemy target's SPD by #3[i]% for #4[i] turn(s). Only 1 Dimension Effect created by allies can exist at the same time.
The base chance of applying debuffs to targets hit. The final probability is affected by the attacker's Effect Hit Rate and enemy targets' Effect RES.
Traces
Eidolon
The maximum stackable count for the Trace "Summation" increases by
When his Talent's Follow-Up ATK hits a target, for every debuff the target has, deals Imaginary Additional DMG equal to
Unleashes an extra attack on the target. This effect is triggered automatically when requirements are met.
Debuffs are negative status effects that render units weaker. Unless otherwise specified, debuffs can be dispelled.
Causes the target being hit to take extra DMG, which is not considered an attack.
Ultimate Lv. +2, up to a maximum of Lv.
When triggering the Talent, additionally regenerates
Skill Lv. +2, up to a maximum of Lv.
Additionally increases the trigger count for "Wiseman's Folly" by
Unleashes an extra attack on the target. This effect is triggered automatically when requirements are met.