Of course, he then came to his senses, turned traitor, and tried ineffectually to attack me (playing as Impa, because one of her combos is epically overpowered against giant bosses). I just ignored him instead and splatted the Dodongos. I'm not sure his pride will ever recover.
Speaking of overpowered combos, I stumbled across another trick. Some missions in Adventure Mode where "all attacks are devastating" - this is essentially InstaGib mode. Previously I've just waded in and relied on the fact that the player can actually survive one hit, but this time I had a go at taking pot-shots with the bow. Normally the bow is only useful against very specific enemies, but it still does a little damage... which in InstaGib mode is enough to churn through vast hordes of enemy captains while staying out of range of them.