High 7-A?
Oh yes, my favourite tier.
I've got to contribute to personality and a bit to abilities:
The personality
This guy (or girl, i don't know yet) will have not only one, but multiple personalities, representing each one of us as several individuals creating one being. It could be multiple, a happy and cheergul, analytic and cold, another one that could be a determined, never giving up personality and maybe hot headed, and one that could be more of a psychopath that hears multiple voices in his head. This could be also added as a weakness, as when he loses the control of all his personality his grasp on reality becomes too loose to be relevant.
TL;DR: This person will have multiple personalities that he may control most of the time, but when he loses the ability to do so, bad things will come ahead for him.
The abilities
As previously mentioned, this individual may have multiple personalities (which i think it is listed as an ability?). I also thinked of him "dividing" each personality, creating multiple copies of himself for each personality he has (think of Raven, of Teen Titans. iirc on one of the episodes, in her head, multiple personalities with different bodies appeared, something like that). But, when he loses the ability to control them all in his head and becomes mentally unstable, he may not be able to control them all.
I also thinked he may be a great fighter but not in the conventional sense, more like on the "unconventional" sense. He may grab things from the environment and treat them as weapons, like using a wooden branch like if a sword it was, or using a bottle for penetration, among many, many other things.
This is my first suggestion. I think it is fine, i will look further on others. This will be truly interesting.