Bloodbath attack
rogue attack 19
Melee weapon
Requirement: wielding a light blade.
Target: one creature
Attack: Dexterity vs. AC
Hit: "3[W] + Dexterity modifier damage, you knock the target prone, and it takes ongoing damage equal to your Strength modifier (save ends)."
Effect: until the end of the encounter, whenever you hit the target, the target takes ongoing damage equal to your Strength modifier (save ends).[MP:83]
Bloodbath attack is a daily power available to rogues at 19th level.