Hidden Jutsu... Devil's Sin! (Kakashi hatake x reader)

There was once a young girl named (y/n). Her parents were known because of the fight against the nine tailed fox. She became a Jonin extremelly fast because of her gekkei kenkai. But that genkai never existed before her because she is... Unique. This girl has always been alone, she never trusted anyone, she always has been emotionless. That's because of a past that no one knew or discovered. She never died. It's been 3000 years and she is still alive... She lived through an era no one knew ever existed. She ran away after her husband died. She still had that power, that chakra in her... After all those years, her past still haunted her... But she saw her husband from years ago in someone, who brought her back to life. She had no hope, she had lost her soul. The Titan era had broken her. All the death she witnessed, she couldn't bear it so she hid herself in her heart. But a scar opened after she met team seven...