Balthamos

From Srafopedia

An angel of low rank, one of Will's angelic guides who with Baruch discovered a secret about the Kingdom of Heaven and did not believe Lord Asriel would trust them unless they could take Will and the Subtle Knife to the Adamant Tower to prove their loyalty. Like all of his kind he is wise beyond human understanding, though he has a very sarcastic nature. The love he shares with Baruch allows them to communicate with each other across great distances. At the end of The Amber Spyglass, he kills Father Gomez by drowning him when he has fallen into a stream in the Mulefa's World. After this, Balthamos vanishes.