Inspired by Quatermass's challenge of Harry Tohsaka challenge but changed found here /topic/100035/169201055/1 Message Quatermass if you do attempt the challenge. Also inspired by the the story snippets of both Separated at Birth and Hadrian Kotomine by Quatermass. Also includes elements inspired from Harry lefratts story Harry and the shipgirls a hp/kancolle snippet collection.
"Harry" is born in the fate/stay universe as the twin brother of Sakura. Then abducted by Dumbledore using Fawkes when he was 1 year old and given to potters after blood adopting him through lily and James. Reason no one questions that there was a male sibling of Sakura was parents oblivated, rin too young, kariya oblivated with it coming back by the end of 4th grail war and Sakura remembered someone male but nothing else caused by the worms.
Gives him magic from James and eyes from Lily. Gets slightly less Asian features and slightly more Caucasian features. Potters are killed by Voldemort and Harry is sent to Dursleys. Lives with them for 6 years/until he is 7, then Fawkes takes him back honing in on Tokiomi's signature. Misses him by hours, gets taken to a police station near the civic center. He is then caught in the fire, getting adopted by Kirei. Kirei disposes of the horcrux, and discovers he was born in the city despite having Caucasian features. (magic bull). Lives until he is 15, then gets taken back to Hogwarts by the Goblet. GoF occurs with him actually having to save Luna (Needed someone, can't take from F/S cause pairing reasons) from the lake.
Goes to gringotts for gems to research on and to see what artifacts he has. Learns that there is no artifacts in there, but there is a shed on a potter property that holds what his family has collected over the years.
Learns he is actually blood adopted by the potters, and his real parents are the tohsaka's with Sakura as his twin.
Discoverers in the shed a broken part of Clarent and decides to use it to help summon Berserker for Harry's later Grail War in 50 years
End of tournament, gets taken by Fawkes to Zelrech, but before stops over at gringotts for converting money to actual gold. Gets back and enters the grail war, master of Berserker.
It's a mess I know. If you want to take this and run with it please do so, the previous chapter will be getting an slight expansion coming soon (whenever i type it up)