If an evil villain took over the world, enslaved humanity, or blew it up, what could he possibly do next?

We all hear about these evil villains doing evil things. But what happens after that?

If you take over the world, you’ve accomplished your lifelong goal. I mean, how much more power do you need to satisfy yourself?

If you enslave humanity, what would you want to do next? Build an evil army? Take over other planets? Over the universe???

What about blowing it up? You’d die too, ya know. Seriously, what’s the point of annihilating your home planet?