The Demon King Overrun by Heroes

[By the Studio that brought you <Surviving The Game as a Barbarian> and <The Player Hides His Past> and <Heavenly Grand Archive’s Young Master, and many more!> ] After diligently following the “demon king’s standards,” I ended up getting killed by the heroes. What, my tower and I are a custom-made hunting ground for heroes now? With this chance at life regained through regression, to hell with the damn demon king’s standards! This is the story of surviving as the hard-headed(?) demon king, Berje!