Novel info
Death After Death (Roguelike Isekai)

When Simon dies, it turns out there's more to combat than lightning reflexes with his controller, and the path to becoming a hero is more brutal than he can imagine as he descends into The Pit. Death after Death is a dark, time loop/Isesaki story with roguelike elements, that explores some of the common tropes in a different light.
This story is all about character development. It starts slow, and it never stops, as our protagonist improves slowly but surely, death after death after death.