Seoul Station's Necromancer서울역 네크로맨서

at the beginning of the novel, the MC wasn't that strong on the previous world, relatively speaking. It was said he could control a small country and not be too bothered because it was filled with death and unsuitable for basically anyone but a necromancer. Everytime they refer back to him on that previous planet, he's stronger. To the point that eventually he's on par with the literal gods and everyone was terrified of him because no one could stop him. Again, this is him before the story takes place. It's basically flashbacks to the same point in time but he's drastically stronger each time because the author changed his mind on the power scaling or something. It's not the level of strength he reaches that bothered me, it's the constant retconning that wasn't even necessary.