Top augment choices for Ornn include Heavy Hitter (Silver), Tank Engine (Gold), Goliath (Prismatic).
Overall
Tank Engine
Tank EngineGain increased size and percent bonus Health per takedown.
Tier: S+
Pick %: 25%
Goliath
GoliathBecome large, gaining @HealthAmp*100@% Health and @AFAmp*100@% Adaptive Force.
Tier: S+
Pick %: 24%
Courage of the Colossus
Courage of the ColossusGain @TotalShield@ Shield after Immobilizing or Grounding an enemy champion.
Tier: S+
Pick %: 19%
Silver
Heavy Hitter
Heavy HitterYour Attacks deal additional physical damage equal to @HealthPercent*100@% of your max Health.
Tier: S+
Pick %: 17%
Clothesline
ClotheslineThere is a tether connecting your team, deals constant magic damage to enemies it touches.
Tier: S+
Pick %: 12%
Desecrator
DesecratorImmobilizing enemy champions grants you permanent Cursed Power. Gain Armor and Magic Resistance based on your Cursed Power.
Tier: S+
Pick %: 12%
Gold
Tank Engine
Tank EngineGain increased size and percent bonus Health per takedown.
Tier: S+
Pick %: 25%
Celestial Body
Celestial BodyGain @Health@ Health, but you deal @DamageReduction*100@% less damage.
Tier: S+
Pick %: 18%
Quest: Steel Your Heart
Quest: Steel Your HeartRequirement: Possess Heartsteel with @StackThreshold@+ stacks. Reward: Multiply your Heartsteel stacks by @StackMultiplication@. Increase your Health Regeneration by @StacktoRegenConversion*100@% of your Heartsteel stacks.
Tier: S+
Pick %: 9%
Prismatic
Goliath
GoliathBecome large, gaining @HealthAmp*100@% Health and @AFAmp*100@% Adaptive Force.
Tier: S+
Pick %: 24%
Courage of the Colossus
Courage of the ColossusGain @TotalShield@ Shield after Immobilizing or Grounding an enemy champion.
Tier: S+
Pick %: 19%
Dreadbringer
DreadbringerGain an aura that continuously harvests permanent Cursed Power per enemy champion inside. Gain max Health based on your Cursed Power.