Reincarnated as a Demon Lord

I died. I thought I was really dead, but then I reincarnated in the Demon Realm and became a Demon Lord. I thought this was the start of my life of lavish spending, but my little succubus maid told me I was bankrupt. That's fine, though. I still have underlings. I'll have them make me rich. What? I don't have a single underling, and you're the only one? That's fine. I'm a Demon Lord, and I'm invincible! I'll make my own fortune. What the heck? I'm going to die too?

This is the story of a shut-in who becomes a Demon Lord and fights his way from the Demon Realm to the Holy Realm, then on to other worlds.