Bane of the Powerful is a Legendary Gem in Diablo III. It can only be socketed into Amulets and Rings, and drops from Greater Rift Guardians. It gives a temporary boost to damage (stacks with other similar modifiers, but not multiplicatively) after killing a Rare Monster, a pack of Champion Monsters, a Unique Monster, a Boss, a Treasure Goblin or another player. Upgrading only increases the duration. At rank 25, it also gives a healthy bonus to damage against elites and damage from elites reduction.