Hundreds Years After I Was Called [Just Corpse], I’ve Become Strongest Undead When I Woke Up

Zion, a solo adventurer, recklessly entered a dungeon beyond his ability.Alas, that was the last thing he did. Wandering inside a dungeon for hundreds of years, as an undead, he kept advancing into the dungeon. Slaying monsters left and right until his undead body underwent ‘evolution’ many times