What if I Was Reincarnated as a Misfortune Villain Aristocrat and Killed the Last Boss, While Ignoring Original Story?

The main character is reincarnated as the miserable, villainous aristocrat Wilheim von Cornelius. To change the miserable fate that awaits him, he takes quick action. “Let’s kill the last boss.” He prepares himself and sets off to kill the last boss , who for some reason is hiding in the neighbourhood.. “Giggle. I’ll be looking after you from now on, okay?　Master Wilheim .” The witch whom he should have killed has resurrected and, as a result, he is cursed and possessed! Having gained unusual magical power, Wilheim accepts the reality and searches for a new way to avoid further misery. This is the story of a lazy and arrogant villainous aristocrat who, despite his arrogance, makes an effort and joins forces with a last boss to overcome the misery. If only he could become stronger – even the death flag could be broken? *Death flag doubled: ⁉︎