^^^Ah, Kingdom Hearts.  Looks pretty badass, actually!

Well in that case, just use the force against him.

Play as Ven. Spam dodge roll and Thunder Surge. Spam dodge roll. Your best time to heal is when he fires that X-Blad thing at you, since it's his slowest attack.

That's about all the advice I can give you. He's a boss the developers can't beat.... Good luck.

I do all that (except Fire Surge, cause Fire is awesome). Anyways... you can heal more often than that, like right after Doom Hook and his Fire Surge. He's just hard. 

Also, did you read the OP? No hints or tips please.

Ah, my bad. I misread the OP.

Thoughts on him don't really extend beyond "Ohai *gets killed*" repeated ad infinitum. I've yet to beat him and I'm level 45. I'm pretty sure he was made for the sole purpose of enraging players.

Didn't pay attention to that part. Sorry.

I defeated him at level 52, with Aqua.

My strategy was no biggie.

Edit - Sorry, didn't read the no tips part. Although, you already know all of my tips

I guess Aqua's Cartwheel sucked instead of Ven's Dodge Roll.

Haven't tried it with Ven yet, so I don't know how much of a difference it would have made.

Though Dodge Roll does have more invincibility frames than Cartwheel, all of his attacks can be dodged well enough with Cartwheel. 

The problem was trying to figure out the right moments in which to attack him and the moments to back away, once he went invisible. That was what extended the fight for me. The first part of the fight was actually pretty smooth for me, once I figured out how to make him use the flaming X attack.