Morgoth
Ainulindalë and Valaquenta
Melkor must be made far more powerful in original nature. The greatest power under Eru. Later, he must not be able to be controlled or 'chained' by all the Valar combined. Note that in the early age of Arda he was alone able to drive the Valar out of Middle-earth into retreat.
Morgoth
Morgoth Bauglir ([ˈmɔrɡɔθ ˈbau̯ɡlir]; originally Melkor [ˈmɛlkor]) is a character, one of the godlike Valar) and the primary antagonist of Tolkien's legendarium, the mythic epic published in parts as The Silmarillion, The Children of Húrin, Beren and Lúthien, and The Fall of Gondolin. The character is also briefly mentioned in The Lord of the Rings.
Morgoth
Melkor is the most powerful of the Valar but he turns to darkness and is renamed Morgoth, the primary antagonist of Arda). All evil in the world of Middle-earth ultimately stems from him. One of the Maiar) of Aulë betrays his kind and becomes Morgoth's principal lieutenant and successor, Sauron.