Lucifer

Lucifer was a powerful multiconscious being that was born of the universe itself and exists as the human epitome of the Devil. He is remembered in fiction for being the malevolent being that tempted Faustus, as well as the archenemy of God and Jesus in the Bible.

Appearance
Though his true appearance is ultimately unknown, since there is no record of him before the Big Bang, it was heavily hinted that Lucifer was spectacularly beautiful and the true definition of magnificence. He was so beautiful that God loved him as his most treasured child, but this was also on account of Lucifer's genius and diligence. However, his appearance dramatically changed as a result of his imprisonment and the way he is perceived by other beings is terrifying.

When he appears to Faustus, Lucifer towers several feet over men, and wears a voluminous black cloak and hood that consists of swirling, violent shadows that conceal a huge deal of his features, including his face - however, golden eyes can be faintly seen. He wields a huge scythe made of black wood with a shining silver blade almost as long as a grown man is tall. When the Doctor once removed his hood, he claims he saw his own face instead. Lucifer's feet aren't seen, but his arms and hands are skeletal and deathly thin. The reason for Lucifer's appearance in this state is because God wanted to ensure that his beauty would never be observed or speculated in full capacity ever again.

Personality
Lucifer is the personification of evil, genius, cunning, malice, chaos and malevolence in the universe, and as a result is absolutely monstrous. He is extremely cruel, being entirely willing to be ultimately responsible for genocide, if not omnicide, if it meant that he could achieve what he wanted in the end. He was extremely intelligent and an unrivalled manipulator, remembered for being exploitative and a cunning sociopath who could upturn the allegiance of entire systems into civil war. It is confirmed that Lucifer was once absolutely magnificent once, upon the creation of man, but once he rebelled against who was apparently God Himself, Lucifer was imprisoned and as a result became extremely bitter and vengeful, but also vindictive to a vicious extreme - he would react furiously at the mention of anything that acclaimed God. Lucifer was also extremely arrogant and narcissistic, having rebelled against his God to take power formhimself under the impression that he was superior in right to such a being.

Powers
Lucifer is one of the most powerful beings in the universe, as a result of being born before it, but his powers are dramatically decreased as a result of having to exist in a universe with more solidity to it and thus more limitations to what he could do. Even so, Lucifer was still terrifyingly powerful. He is better remembered for being a master of exploitation and manipulation, and is able to subconsciously know how to exploit people.

Lucifer is able to possess other sentient beings and even technology. He is able to speak, with his own voice, through other people, and this includes animals such as horses and wolves. Because of this, Lucifer is consequently present in the minds of every human who has ever lived, being the epitome and manifestation of their cruelty, doubt, ambition and selfishness. He is able to read other people's minds through being a manifestation of their traits and can interpret telepathically how they feel without having to make them tell him, but beings with extremely powerful minds in terms of resilience, such as the Doctor, can resist him.

Lucifer is superhumanly strong, being able to lift a fully-grown human being off the ground, even when he manifests himself in the body of a human being. He was strong enough to physically overpower and even rip apart other beings like him, since he fought with God for centuries before time existed and physically dismembered hundreds upon hundreds of God's most powerful creations to have existed even before the Big Bang. Even in his imprisonment, he was still incredibly strong, smashing down the doors of a castle with one measured blow of his scythe.

Lucifer has absolute authority over his realm, over what is apparently Hell itself. He has earned unparalleled control over the other beings who reside, and thus is able to open portals to Hell and drag other beings into Hell where they are completely under his control and mercy. He can resurrect the occupants of Hell as spectres that are only apparently shadows of what they originally were, since their souls are still in the clutches of Lucifer.