Talon's abilities wound champions for a short duration, stacking up to three times. When Talon basic attacks a fully wounded target, they bleed for 80-280 (+2.1 per bonus attack damage) physical damage over 2 seconds (levels 1-11). Talon's abilities will also wound all monsters for 120% damage.
It should be called Mercy if the passive is something like : Talon deals 10% additional damage with his autoattacks to any target with health bellow 25%.