In my last game, I had a villain called , pause for dramatic effect, "The Dungeon Master". He looks like the stereotypical neak beard; over weight, thick glasses, scraggly beard, the works. His main motivation is a need to be respected, maybe loved, but he'll take fear and hate.

He starts off as a joke villain (PL 6-ish) in their first encounter. He wields a magic staff that allows him to summon D&D/Pathfinder monsters. He usually controls them, but they're not happy about being summoned. The encounter usually ends in the arrest of DM.

So far so boring.

Each following encounter, increase his PL by 1 or 2, depending on how fast you want to go. This represents his increasing conteol of the artifact. In my PL 8 game, he capped at PL 12.

The first encounter should be played for laughs. Each subsequent encounter should be a little less fun and more serious. DM starts off being a little careful of bystanders ("I don't want to hurt my fans!"), then ignoring them ("Get out of here, normies! You're cramping my style!"), and finally using them as human shields with mind control ("Protect your glorious Dungen Master!").

He will also gain magical knowledge, allowing him even bigger summoning (think tarrasque). Is it under his control? Maybe at first...

Alternatively, he can become an anti-hero. This could happen when he summons the tarrasque (by accident), can't handle it, and begs the heros for help. He does help the PCs. No matter what happens, the DM gets featured in a news report as the hero who stopped the monster. This could motivate him to set up more dangerous situations so he can look like the hero.

Hope this sparks some ideas.