No Kill Quite Like Overkill (Razor)

Achievement unlocked: No kill quite like Overkill!

Deal more than twice the damage a defeated enemy had as health left in a single strike

+50 XP (XP Reduction included)

+2 Drops of the beaten enemy

+2 Stat points

Ring of the Slayer

Reference
Unlocked in Chapter 41 "And This Time, He Actually Fights The Boss" (Razor)