Blood Demon Reincarnation

kang san is a bottom % tanker with no talent, abilities, or skill. misfortune follows him until a divine messenger appears before him one day. “you were the blood demon in your past life.” to atone for his past life’s sins, he must endure harsh trials. but in return, he will receive immense rewards? “fine. i’ll do whatever it takes.” can a weak f-rank tanker drenched in blood change his fate?