bio of Servant

Y/n was a saber Servant a 0 star type ( like Angra ) who was the rares of all, not very strong but loyal to gudako his máster, however one day at the misión His " companions" brutally murder him and even left few scars and His body was broken but His soul stay that a black grail turn him into a killer, a broken servant who does not require maná transfer and decides to take Revenge on those who Defy him.

how Will he suffer to His cruel and reality Fate?

i do not own any fgo characters nor other Fate series they belong to there original owners