Book: Tower Allies.
Cayde-6 was a daring Hunter with a fast ship, a quick gun hand, and an eye on the legendary Vault of Glass. Of course he couldn't say no to a challenge - not even the notorious Vanguard Dare.
He lost the bet, to his immense regret. Now, following in the footsteps of his fallen friend Andal Brask, it is Cayde's turn to oversee his far-flung brethren as the Hunter Vanguard in the Tower. He works dutifully, but longs for a chance to get back into the fight.