An example of bane is what kryptonite is to Superman.
The bane of my existence.
My cruel teacher was the bane of my existence.
The defender was the bane of my scoring hopes, blocking my shot from the goal.
The winter was the army's bane; his freezing forces had to retreat.
(archaic) The ocean bane sank their ship, drowning everyone on board.
They called her "Wolf's Bane," because she killed many wolves.