Godsbane

The godsbane is an inventory item found in the tool section of your inventory. When selected the Arisen takes the dagger and turns it to his chest. Pressing the plunge option kills you. Literally you die and are forced to return to you last checkpoint. The only time one can use it is once you take the seneschals place at the end of the game.

Note the blade cannot be used in any other way it is not a weapon and is next to useless unless reaching the ending