When Yuya realised he was only part of a whole, everything made so much more sense.
It was soothing, in a way, to have a neat explanation. To finally, finally have a label for the feeling that had been plaguing him his entire life. What was decidedly NOT soothing was what came along with that label. Namely, the knowledge that he and Zarc were one and the same. After all, who on earth would like hearing that they were technically Satan incarnate? A complete lunatic, that's who. Or a destructive ego-maniac. Certainly not a pacifist like Yuya.
But here's the thing: Yuya WAS Zarc.
A partially amnesiac Zarc, with an insane commitment to idealism and a pacifistic nature.
It was an endlessly odd situation. One that brought no end of identity crisis'. And the major problem was: all the counterparts had influence on the original. It was not something any of them advertised, of course. Why would they? All four of them had gotten sick and tired of being tugged this way and that in an inter-dimensional war. Tired of reacting to things outside their control. But anyway, that wasn't the point. The point was that Yuya, Yuto, Yugo and Yuri had influence over Zarc.
Why wouldn't they? They were technically separate parts of Zarc's personality given form. Fragments. Each had changed and developed over the fourteen-year long separation. Which led them to the next problem.
What the hell were they going to do now?