Æsahættr

From Srafopedia

The name by which the cliff-ghasts refer to the Subtle Knife. The name was made up from two Norse words meaning God and death. Literally, the word means "God Destroyer", hence the idea that perhaps the knife was intended to destroy the Authority or perhaps it was a metaphor describing it's power. The angels Balthamos and Baruch think that the knife will be a valuable weapon to Lord Asriel (it would be to anyone) in his war against the Authority and so try to persuade Will to take it to him.