That's a very good point. When I first read through it, you character seems to be close to par with the Eight at their current stage. Now, upon reaching the later stages, this will not be an issue, however it is an unfair advantage over the other combatants. The idea behind these battles is for weaker characters to defeat a stronger one through teamwork and tactics. I don't have any problems with the abilities themselves, just the magnitude of them. I would say to scale things back a bit, perhaps build him as he was when he was younger, or still in training. Add some tangible limits to how often he can use his more powerful abilities, or state how much it drains him, and I think you should be good.