There's some great info here but I just felt the need to write a solution regarding the last boss.
You will enter an arena where a ton of his minions drop down to attack you. Dispose of them how you see fit. Once they stop spawning, shoot crowe until he drops. When he does, just charge him and spam B.
The first time I attempted this, he glitched into the wall. Do not shoot your weapon at him. This solution isn't guaranteed to work first time, but it works.