Apocalypse Descends: From the Start, I'm the Corpse King

[Smart protagonist + supernatural abilities + not a saint + decisive and ruthless + steady power progression + zombie from the start]

What! I’m a zombie from the start?

After a friend scammed me over the phone and sold me off, I turned into a zombie.

Thirty years east of the river, thirty years west of the river.

Watch me grow stronger step by step, take my revenge, and build an empire of my own!