Each of Warwick's autoattacks deal 3 / 3.5 / 4 / 4.5 / 5 / 5.5 / 6 / 6.5 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 (2.5 + 0.5 / 1 at each level) additional magic damage and heal him for the same amount. Each successive attack against the same target will stack this amount of healing and damage up to a maximum of 3 stacks. The stacks remain for 4 seconds.
Eternal Thirst is a passive ability that grants Warwick an on-hit effect.
The attacks will apply other on-hit effects and can critically strike as normal.
The bonus damage from Eternal's Thirst can not critically strike.
The healing portion is independent from the damage portion of the ability, meaning the heal is always the same regardless of the damage dealt to the target.
Disregarding bonus Attack Damage, Eternal Thirst is an equivalent of ~ 5% / 10% / 15% Lifesteal at level 1 to ~ 14% / 27% / 41% Lifesteal at level 18.
Cooldown: 10 / 9 / 8 / 7 / 6
Cost: 70 / 80 / 90 / 100 / 110 mana
Active: Warwick swipes at a target enemy, dealing magic damage for the greater value between a flat minimum amount or a percentage of the target's maximum health, plus additional bonus damage based on his ability power. Hungering Strike can only deal the flat damage to minions and monsters.
Warwick heals himself for 80% of the damage dealt (after reductions).
Max Magic Damage To Champions:8 / 10 / 12 / 14 / 16% of target's maximum health(+ 100% AP)
Upon sensing an enemy, that enemy will become visible to Warwick and his allies, even in fog of war or inside a bush.
Stealthed units will not be revealed even if they are sensed by Warwick. He will still gain the movespeed bonus, but he will not be able to see the unit.
Cooldown: 90 / 80 / 70
Cost: 100 / 125 / 150 mana
Active: Warwick blinks to the front of an enemy champion and channels for 1.5 seconds, suppressing the target for 1.8 seconds and dealing magic damage 5 times in 1/3-second intervals. Warwick gains 30% life steal for the duration. Each damaging strike applies on-hit effects, life steal, and maximum stacks of Eternal Thirst.
The lifesteal from Infinite Duress affects magic damage on-hit effect items such as Nashor's Tooth or Wit's End, unlike normal lifesteal. It is uncertain whether additional lifesteal stacks and works alike with the 30% lifesteal from this ability.
Including Eternal Thirst's damage, Infinite Duress will deal a total of 332.5 / 340 / 347.5 / 355 / 370 / 470 / 485 / 500 / 515 / 530 / 630 / 645 / 660 (+2.0 per bonus attack damage) magic damage. This is assuming you take ranks in Infinite Duress at level 6, 11 and 16.
All the strikes have the potential to trigger and apply Spellblade but will only hit once because of the internal cooldown of this item.