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Honkai Star Rail Dr Ratio best build, Ascension materials, Traces, and Light Cones

Everything you need to know about Dr Ratio in Star Rail.

a dark blue space background with splash art of dr ratio who is a short blue haired man holding a stone book and dressed in blue trousers and a small white and black robe
Image credit: Eurogamer/HoYoverse

Dr Ratio is a 5-Star Imaginary character of The Hunt path who was added to Honkai: Star Rail during version 1.6.

While Dr Ratio is featured as the boosted 5-Star character on his Panta Rhei Banner in version 1.6, he will eventually return to Honkai Star Rail at some point in the future when the Banner schedule cycles back to him (and he's free if you login before the end of version 2.1!)

Whether you have him, or want to prepare for if you do Warp for him successfully, it's good to know the best Dr Ratio build, including his best Relics and best team. It's also handy to learn what his Eidolons are, and what Ascension materials and Trace materials are needed to level up Dr Ratio to his full potential.

Dr Ratio materials and stats:

Dr Ratio build:

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Honkai Star Rail Dr Ratio's kit

Dr Ratio is a 5-Star Imaginary character of The Hunt path who scales off attack and is best used as a follow-up attacker against debuffed enemies.

All of the percentages mentioned below are based on Level 1 Traces.

Here's a summary of Dr Ratio's kit in Honkai Star Rail:

  • Element: Imaginary.
  • Path: The Hunt.
  • Rarity: 5-Star.
  • cropped splash art of dr ratio who is a short blue haired man holding a stone book and dressed in blue trousers and a small white and black robe
    Image credit: HoYoverse
  • Basic Attack: Mind is Might - Deals Imaginary damage equal to 50% of Dr Ratio's attack to a single enemy.
  • Skill: Intellectual Midwifery - Dr Ratio deals Imaginary damage worth 75% of his attack to a single enemy.
  • Ultimate: Syllogistic Paradox - Deals Imaginary damage equal to 144% of Dr. Ratio's attack to a single target enemy and applies Wiseman's Folly. When Dr Ratio's allies attack a target with Wiseman's Folly, Dr Ratio launches his Talent's follow-up attack for one time against this target. Wiseman's Folly can be triggered for up to two times and only affects the most recent target of Dr Ratio's Ultimate. This trigger count resets after Dr Ratio's Ultimate is used.
  • Talent (passive ability): Cogito, Ergo Sum - When using his Skill, Dr Ratio has a 40% fixed chance of launching a follow-up attack against his target for one time, dealing Imaginary damage equal to 135% of Dr Ratio's attack. For each debuff the target enemy has, the fixed chance of launching follow-up attack increases by 20%. If the target enemy is defeated before the follow-up attack triggers, the follow-up attack will be directed at a single random enemy instead.
  • Technique (overworld ability): Mold of Idolatry - Dr Ratio creates a special dimension that Taunts nearby enemies, which lasts 10 seconds. After entering battle with enemies in the dimension there is a 100% base chance to inflict a 15% Speed Reduction on enemies for two turns. Only one dimension created by allies can exist at the same time.
  • Bonus Trace 1: Summation - When Dr Ratio uses his Skill, for every debuff on the target, his Crit Rate increases by 2.5% and Crit Damage by 5%. This effect can stack up to six times.
  • Bonus Trace 2: Inference - When his Skill is used to attack an enemy target, there is a 100% base chance to reduce the attacked target's Effect Resistance by 10% for two turns.
  • Bonus Trace 3: Deduction - When dealing damage to a target that has three or more debuffs, for each debuff the target has, the damage dealt by Dr Ratio to this target increases by 10%, with a maximum increase of 50%.

Honkai Star Rail Dr Ratio Ascension materials

Suppressing edict material menu image.
Suppressing Edict. | Image credit: HoYoverse

You need to use Dr Ratio Ascension materials to upgrade stats like his health, attack, defence, and critical hit effectiveness. You need to get a lot of Suppressing Edict and Thief's Instinct-based materials for Dr Ratio to fully upgrade his capabilities.

In total, the Dr Ratio Ascension Materials in Honkai: Star Rail are:

  • x15 Thief's Instinct
  • x15 Usurper's Scheme
  • x15 Conqueror's Will
  • x65 Suppressing Edict
  • 308,000 Credits

For more details, here's what Dr Ratio Ascension materials you need per level:

Dr Ratio Ascension level Dr Ratio Ascension materials Credit cost Reward
Level 20 x5 Thief's Instinct 4,000 x1 regular Star Rail Pass
Level 30 x10 Thief's Instinct 8,000 None
Level 40 x6 Usurper's Scheme, x3 Suppressing Edict 16,000 x1 regular Star Rail Pass
Level 50 x9 Usurper's Scheme, x7 Suppressing Edict 40,000 None
Level 60 x6 Conqueror's Will, x20 Suppressing Edict 80,000 x1 regular Star Pass
Level 70 x9 Conqueror's Will, x35 Suppressing Edict 160,000 None

Honkai Star Rail Dr Ratio Trace materials

menu image of arrow of the starchaser
Arrow of the Starchaser. | Image credit: HoYoverse

Just like Ascension, to get the most out of using Dr Ratio you will have to level-up his attacks and passive abilities by using Trace materials, which vary from character-to-character.

For Dr Ratio, you need to use a lot of Thief's Instinct and Arrow-based materials to fully upgrade his capabilities. In total, to upgrade all of his abilities, the Dr Ratio Trace Materials you need are:

  • x8 Tracks of Destiny
  • x12 Past Grievances of the Planet-Boring Disaster
  • x18 Arrow of the Beast Hunter
  • x41 Thief's Instinct
  • x56 Usurper's Scheme
  • x58 Conqueror's Will
  • x69 Arrow of the Demon Slayer
  • x139 Arrow of the Starchaser
  • 3 million Credits

Version 2.2 with Robin and Boothill is nearly here! Meanwhile, in version 2.1 we have Aventurine and Jingliu running, so make sure to redeem those new codes for Stellar Jade if you want them or future characters - and check all characters out on our regularly updated tier list. For everything else, we have pages on the next Banner, Ministry of Education quiz answers, how to get more Star Rail Passes, and an English voice actors list.


Honkai Star Rail Dr Ratio Eidolons

By getting duplicates of Dr Ratio from Warping on his Banner, you will receive his Eidolon. This material allows you to unlock Eidolon levels, with each upgrade either improving an existing attack or passive ability.

drip marketing for dr ratio, a blue haired man dressed in blue and white clothing holding  what looks like a stone book, with his name, path, and element in text
Image credit: HoYoverse

Here are all of Dr Ratio's Eidolons in Honkai: Star Rail:

  • Pride Comes Before a Fall (E1): The maximum stackable count for the Trace 'Summation' increases by four. When a battle begins, Dr Ratio immediately obtains four stacks of Summation.
  • The Divine is in the Details (E2): When his Talent's follow-up attack hits a target, for every debuff the target has, additionally deals additional Imaginary damage equal to 20% of Dr Ratio's attack. This effect can be triggered for a maximum of four times during each follow-up attack.
  • Know Thyself (E3): Increases the level of Dr Ratio's Ultimate by two with a maximum upgrade level of 15, and increases the level of his Basic Attack by one, with a maximum upgrade level of 10.
  • Ignorance Is Blight (E4): When triggering his Talent, Dr Ratio additionally regenerates 15 Energy.
  • Sic Itur Ad Astra (E5): Increases the level of Dr Ratio's Skill and Talent by two, with a maximum upgrade Level of 15.
  • Vincit Omnia Veritas (E6): Increases the trigger count for Wiseman's Folly by one, and the damage dealt by Dr Ratio's Talent follow-up attack increases by 50%.

How to play Dr Ratio in Honkai Star Rail

Your goal is to use Dr Ratio's Ultimate on an enemy to implant the Wiseman's Folly effect, then attack that target with your team for the chance to trigger Dr Ratio's follow-up attacks. If the target with Wiseman's Folly has at least three debuffs on them, then you have the maximum chance available to launch Dr Ratio's follow-up attack.

Ideally though, you want six debuffs on an enemy so Dr Ratio can benefit from the maximum Crit Rate and Crit Damage he gains from his first bonus trace ability, Summation.

Due to the way Dr Ratio's kit is designed, he is best used in single-target encounters, like against tough bosses in the simulated universe or Memory of Chaos. He can absolutely still work in multi-target battles, but Dr Ratio just won't be doing as much damage as he could be.

Dr Ratio standing in Herta Space Sation with a hand below his chin in a thinking pose.
Image credit: HoYoverse

Best Dr Ratio teams in Honkai Star Rail

Dr Ratio has a lot of natural synergy with Nihlity debuffers, as the more debuffs an enemy has, the higher his personal attack damage is. This makes Welt a fantastic partner for Dr Ratio if you're running the 4-piece Wastelander of Banditry Desert on both of them. Silver Wolf is another great pick, as she has a focus on debuffing single-targets, but Pela can also work.

cropped splash art of topaz and numby
Topaz works very well with Dr Ratio. | Image credit: HoYoverse

Remember that DOT (damage over time) effects also count as debuffs, so you can even run DOT Nihility characters like Kafka with Dr Ratio if you need their unique attacks or weakness breaking abilities.

However, the best attacker to run alongside Dr Ratio is Topaz, as she excels in boosting follow-up attack damage for the entire team, and Dr Ratio's abilities combine with Numby to create some amazing follow-up damage potential.

Any Harmony character can work with Dr Ratio in some capacity, but we actually recommend using Tingyun for Dr Ratio to take advantage of her attack and Energy boosts. If you find yourself with spare Skill Points, however, then Bronya can work even better. On the flip side, if you're in desperate need of Skill Points, then Hanya or the upcoming Sparkle can save the day. As a bonus, Yukong can work very well in mono Imaginary teams.

Any Abundance or Preservation character with bonus debuffing abilities like Gepard or March 7th can help in a Dr Ratio team, but you'll generally just want to bring somebody along who can keep your team alive easily. Luocha, Huohuo, and Fu Xuan are best at this.

Best Dr Ratio Relics in Honkai Star Rail

Menu view of the Inert Salsotto Planar Ornament set in Honkai Star Rail.
Inert Salsotto. | Image credit: HoYoverse

According to leaks on Project Yatta, two new Relic sets are coming to version 2.0 in Honkai Star Rail, and one of them (Pioneer Diver of Dead Waters) looks like it will be Dr Ratio's best Relic set. For now, we've detailed his current best Relics in version 1.6 below.

If you have a good set, we think 4-Piece Wastelander of Banditry Desert is currently Dr Ratio's best Relic set for its boost to Imaginary damage and Crit Rate. As with most attackers the 4-piece Genius of Brilliant Stars can substitute if you have good substats on it, as its lowering of an enemies defence is incredibly useful (especially if the enemy is weak to Quantum).

If you don't have good main stats on these two sets and are just waiting until version 2.0 to farm his best set, then we recommend combining the 2-piece Musketeer of Wild Wheat and 2-piece Wastelander of Banditry Desert for their increase in attack and Imaginary damage, respectively. The 2-piece Messenger Traversing Hackerspace can substitute one of these if you need more speed (or it has great substats).

As for farming the Simulated Universe, Inert Salsotto is generally Dr Ratio's best Planar Ornament set, as it increases Dr Ratio's Crit Rate and Ultimate and follow-up attack damage. The Celestial Differentiator, Firmament Frontline: Glamoth, and Space Sealing Station sets can also work if you happen to have better substats on them.

As always, if you're really struggling for Energy, Sprightly Vonwacq can work, as can Penacony, Land of the Dreams if you're running a mono Imaginary team.

Best Dr Ratio Light Cones in Honkai Star Rail

Dr Ratio's best Light Cone is undoubtedly his 5-Star signature, Baptism of Pure Thought. At Level 90 Superimposition 1 it increases his Crit Damage by 20%, and for every debuff on the enemy target, Dr Ratio's Crit Damage dealt against this target increases by 8%, stacking up to three times.

When using his Ultimate to attack the enemy target, Dr Ratio receives the Disputation effect, which increases damage dealt by 36% and enables his follow-up attacks to ignore 24% of the target's defence. This effect lasts for two turns.

light cone banner for dr ratio in version 1.6
Image credit: HoYoverse

If she's not using it, then Topaz's signature 5-Star Worrisome, Blissful is Dr Ratio's next best 5-Star option for its increase to Crit Rate, Crit Damage, and follow-up damage. Yanqing's signature 5-Star Sleep Like the Dead and Seele's 5-Star signature In the Night can also work as Crit stat sticks.

If you don't want to Warp for signatures, then the 5-Star Cruising in the Stellar Sea is your next best option for its Crit Rate and attack boosts. It's available to purchase with Herta Bonds in Herta's Shop.

As for 4-Star options, we recommend either Only Silence Remains or Swordplay. Only Silence Remains is even better when there's two or less enemies on the field, but Swordplay is more suited to single-target encounters, as it's all about building attack stacks by hitting the same enemy repeatedly.

Best Dr Ratio build in Honkai Star Rail

Keeping in mind that the best team comps in Star Rail are very situational, if you want to take advantage of his attack and debuffing potential while keeping him alive, we have compiled what we think is currently the best Dr Ratio build in Honkai Star Rail:

  • Dr Ratio Best Light Cone: 5-Star Baptism of Pure Thought.
  • Dr Ratio Best Relics: 4-Piece Wastelander of Banditry Desert.
  • Dr Ratio Best Planar Ornaments: Inert Salsotto.
  • Dr Ratio Best team comp: Topaz, Tingyun, Luocha.

Remember that the new Pioneer Diver of Dead Waters will most likely be Dr Ratio's best Relic set when it releases in version 2.0, and that Silver Wolf can replace Topaz and Huohuo can replace Luocha if you're in need of more single-target debuffing abilities.

drip marketing for dr ratio, a blue haired man dressed in blue and white clothing holding  what looks like a stone book, with his name, path, and element in text
Image credit: HoYoverse

Dr Ratio is a fantastic DPS at E0 who you can currently get for free, so there's no need to worry about whether its worth spending your Stellar Jade on him! He's a fantastic DPS who has a lot of natural synergy with Nihility and Imaginary characters, so we recommend farming for his materials.

Good luck levelling up Dr Ratio in Honkai Star Rail!

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