The place where the dark-hearted people go is the Underworld, or the Black Abyss. The Underworld is like the Nyovan's hell. It is believed to be the home of a terrible, unholy monster called M'kau, along with his two lesser brothers Asmodok and Keho. They control all that is evil, and decimates anything that is good. M'kau has corrupted many great warriors like Soulkeeper and Lord Kato. M'kau was depicted as an enormous Lava Serpent with four wings, covered in thick spikes. He had a dangerous fire breath that could decimate an entire continent with one blow.
M'kau is the leader of the three Prym Evils. He rules over the Underworld and he has been planning to rule the Material Plane for a long time. He has been possessing Drakoans and other Nyovans for centuries but none have been more successful than Soulkeeper and Lord Kato. He lives behind Hell's Gate in the Underworld, but he is held behind those gates that are bound by an ancient spell by the Autumnmoon, Silverstar, and Nightthunder.
Asmodok is one of the two lesser evils than M'kau. He is depicted as a Minotaur, a man-bull of greek mythology. He is slightly smaller than M'kau, but he is no less dangerous. Asmodok carries a huge axe-staff with him as a strong fire weapon. He has red fur and maroon mane with long sharp horns. Like most other minotaurs, he has hooved feet.
Keho is an enormous water/earth drake. He is said to live in the planet core which is made up entirely of boiling water. However the core has been sealed off since ancient times, before the time of the first Titans. He is supposed to have sixteen horns along his head and neck with a spiked tail. He is very built-up with strong jaws and huge claws. On his back are two wing-like spines that are attached in the middle but run up and down his back. He has four limbs in addition to two smaller ones used for grasping.