There's More to Death

In ages past, before the Grimm, before Dust, humanity thrived normally. However, the world was brought to its knees by a malevolent being. Eventually, bored from its conquest, the being went into hiding. Now, bored out of its mind, the being returns, though not as malevolent as before. In fact, some might call him a lazy bum. Harem, possible lemons, gore.