Leprous Wound is a 19th level avenger Daily attack that was introduced in the 380th edition of the Dragon (magazine).
Leprous Wound
Avenger Attack 19
Your dire strike causes your enemy to fall to pieces.
Melee weapon
Target: One creature
Attack: Wisdom vs. Fortitude
Hit: 2[W] + Wisdom modifier necrotic damage. Whenever the target takes damage from an attack, it takes 10 extra necrotic damage and is slowed until the end of your next turn (save ends).
Miss: Half damage, and the target takes 10 necrotic damage the next time an attack hits it before the start of your next turn.