I Was Assassinated For Crimes I Hadn't Committed Yet, So I Got Up And Went To Work

A crying stranger put a knife in my heart in a university library four days before the sky opened, and he told me I was a devil who would kill millions. He was right about everything except the timing, because when the world awakened I got the one talent nobody could kill and a counter that goes up every second I keep breathing. This is a full manhwa recap of an apocalypse LitRPG where the system hands out dungeons, tiers and world-first announcements, and the weakest man on the leaderboard clears an Easy instance in a hospital gown because he simply refuses to stay dead. Reincarnation, cultivation, an OP MC with an EX-grade cheat, and one time traveler in the corner of the room taking notes. He came back sixteen years to stop me. Do you think he still should?