I'm still really confused... why make a new entire history based of Nagi when he's going t...

I'm still really confused... why make a new entire history based of Nagi when he's going to be eliminated in the end? something just doesn't seems right to me tbh

Why make Nagi such an important character to begin with? I MIGHT be delulu, but I can sense that Nagi will come back, not soon, but maybe later.