A little backstory for those of you who either don't know about Lord of the Rings or haven't read The Silmarillion:
In the beginning, Eru Ilúvitar, he who created all things, created divine spirit beings called the Ainur. He showed to them a theme, His theme, and they were to orchestrate a Great Music for Him. All of the Ainur created one brilliant harmony.... save one. Melkor, later called Morgoth Bauglir, was gifted with the greatest knowledge and power of all the Ainur, but he was interested in his own theme, and he created Discord, and his song was great and terrible. But Ilúvitar silenced and shamed Melkor, and Melkor became spiteful and cruel at heart for his rejection. When the world was made, and the Ainur descended upon the Kingdom of Arda and became the Valar, they created works of art, but Melkor destroyed them. When the Elves were made, one named Fëanor created the most beautiful and pure and holy gems in existence, gems that can purge and burn Darkness and Evil, and they were named the Silmarils. Melkor became jealous of these fine works, and through cunning and deception, he stole away with the Silmarils and encased them in his dark crown of iron (however, being an Evil being, his hand was burned). When learning of this treachery, this rape of his craft, Fëanor damned Melkor to be known as Morgoth Bauglir, The Black Foe of the World. And Morgoth finally made war against the earth and Valar for the rest of time, and forever shall be evil.
Sorry for the long winded introduction, but it helps get an idea of what is wrong with this character. As Morgoth Bauglir, you are the origin of evil in the world. Sauron was but your lieutenant, a Maiar who allied himself to your cause of total domination of the Kingdom of Arda and the world. It is your duty to corrupt the minds and bend the wills of al those to your service, and if you can't succeed in this task, then you must destroy them. You are cunning, and you have the silveriest tongue of anyone. You can summon forth your dark spirits and minnions to aid you, and, if you must get your hands dirty in a fight, you can make use of Grond, The Hammer of the Underworld.