That’s not even how the Flashback Light works, Shirogane. The last time it ‘implanted’ a bunch of memories, they [didn’t stick as well as you might think]. How in the world do you think it’s going to reconstruct someone’s entire persona, much less give them Ultimate talent? Also, did you forget their Ultimate selves had the same personalities as in the prologue, even?

Cue more costume switches to reinforce the fiction. Cheap.