From Blades to Bullets, My Vow Lives On

Jasper Linton, top commander of the Imperial Guard, wakes up to find himself five hundred years in the future, in the body of a descendant who shares his name. While his old acquaintance has become a lonely immortal waiting for their reunion, Jasper promises to protect his three aunts from the most feared assassin guild—only to be surprised by how easily he can overpower them.