Idea for a metro fanfiction i'm writing

( let me know if there is any copyright issues i would have to go through to publish and if i need to have permission to the metro name, and i might use some names from some characters from the books themselves )

The year is 2034. A mercenary known as Dimitri is on the run. He has screwed up badly this time. Now he has almost every faction on his tail. Now he can only trust a few friends his younger friend Alexandr, Yuri and his VSV rifle. But how will he keep running at his age of 50. It will be a test of his trust and his endurance. Will he be able to hide or will his life end with bullet in his head?