Mr. Devil

Mr. Devil otherwise known as Lucifer Satan Devil is as you guessed, the ruler of Hell. He rules over the damned souls and they work at Hell.

In the mortal world, he has a multi million dollar company known as "HellCorps" which is designed around making new inventions and technological advances.

Despite the fact that he is the devil, he is surprisingly friendly to everyone, including Mike and company. There are very few people that bother him though.

The few people that DO bother him though, are the RUC. Oftentimes they would die and be sent down to Hell. They were so annoying that he ends up bringing them back to life just to get rid of them so he wouldn't have to deal with them, only for them to die and come back down again. (unsurprisingly, whenever the RUC is in Hell, they are completely unaware that they're dead... and in Hell... in fact, they even believe Hell is "Paradise," the supposedly special spot in Heaven they wrote about that's reserved specifically for RUC members). You have to feel sorry for the guy.

He even helped Mike upgrade his truck once with an engine that runs the damned souls inside.