Dolorous Stroke

Trope
The dolorous stroke is a trope in Arthurian Legends which usually involves the Fisher King being sinful, then getting struck by the Spear of Destiny. His land turns into a wasteland and he becomes the "Maimed King." The kingdom won't be healed until he is healed.

Balin
Merlin tells Balin that he is cursed to strike the Dolorous Stroke which is a sinful horrible stroke that is only beaten by sinfulness with the stroke that killed Christ.