Dragonhead: As soon as the dragonhead appears (the cannon, I suppose), double jump and Up + B to avoid the blast.
Boomerang shuriken: Double jump over it. Short fall before it comes back, and repeat. Then go and own him.
Spike sword: He'll do a dive and scrape the ground. Wave dodge or jump over it.
Odd fishlike thing: Just duck.
Chaos wings: He'll go into the backround, spread his wings and release 3 red rings around him. You must wave dodge each one, or else you get absolutely owned.
Rampage: Just go behind him. He'll shoot spikes at the ground.
Bullet hand: See result for rampage.
Aura: Just stay away. Not too hard.
Tip: Make sure your not too close when he's teleporting around, as it does some damage. Good luck.