Yeah, completely skipped the second phase, where you have to kill the flying guys, and the third phase where you ride the dragon. You're not supposed to be able to skip it though, it's supposed to sit at 1 HP until final phase. During the dragon phase, you're right, it does REALLY poor damage, which is why you wanna get it really low before he flies off, then when you get to dragon phase, you only have to hit it a couple times.