Okay, after reading James' full profile, I have a few other things I'd like to say. First is that Void, Fire and Earth are elements, not schools of magecraft. Considering James' background, he likely falls into a similar category to Shirou, where they don't have a specific school they ascribe to because "the only real magic allowed to them" is the unique one they were born with (UBW in Shirou's case). Second is that Void is kind of the hallmark of Shikis Tohno and Ryougi, who both possess the Mystic Eyes of Death Perception (a.k.a HAAAAAAAAAAAX). I don't think we want anyone who has anything to do with the Root, Akasha, or the MEoDP in a Grail War RP (though I don't think you meant that when you said "Void"). Third, this ability of his sounds a lot like Imaginary Numbers, which was also pretty hax when Sakura was showing it off during Heaven's Feel. Again though, I doubt that's what you intended.
I hope this doesn't seem like I'm picking on you or anything. I do like the idea, I just think it needs some ironing out. To be clear, nothing with the power set is inherently bad/contradicting canon (he's kinda like Kiritsugu with Imagine Breaker lol), and I'm normally much more lax about canon and stuff than this. I'm just trying to help iron out details so it doesn't cause any problems or confusion later down the line :)
Of course I've probably overstepped my boundaries a bit already. This is all vance's call. Ball's in his court. I just thought I'd mention a few things that stood out to me (minor fixes hopefully, because again I do think the character is interesting and have tried my hand at playing a similar type of magus before).