Chapter 2: extra chap

how should the system work should mc be reincarnated as shirou,s brother or a matou a tohsaka, a emiya or orphan should mc have magic circuits or should he reincarnate in the past in Britain or uruk something like that should mc will get a random flaw and perk at the beginning so give me a few ideas here if he gets a reality marble should mc be transmigrated instead as shinji, shirou or a random orphan what type of kagune should mc have