Father (Fullmetal Alchemist)
An enigmatic being with no known name, "Father" is the central antagonist of the Fullmetal Alchemist manga, and is responsible for the creation of the seven Homunculi (and ultimately the cause for most of the atrocities throughout the story), his children with which he "shares his soul" (thus explaining his title).
"Father" is seemingly rather old in appearance, but it is suggested that he is even older than he appears - at least two or three centuries, if not more. He is a cold and pragmatic person who loathes treachery of his plans, and he may be responsible for the very creation of Amestris itself, as well as for the provocation of every war relating to it. He considers himself an existence far beyond human, comparing them to insects, and anyone who isn't useful in his plans is considered expendable. He also has an unexplained connection with Hohenheim, whose face resembles his and to whom he refers as "it" rather than "he." It appears that whatever connection he has with Hohenheim is not antagonistic, as it appears that Hohenheim knows what "Father" is doing, but has made no attempt to stop him. Also, when he learns that Hohenheim is alive and has had children, he seems to react with excitement.
"Father" has the extremely useful power to nullify all alchemic processes within a large radius of himself, rendering any and all alchemic attacks - no matter how lethal, powerful, or proficient - to be completely null and void against him. He is apparently vulnerable, however, to Xingese and Ishbalan alchemy (a mix between Xing and Amestris alchemy used by Warrior monks), for reasons unknown. It would also seem that he can perform alchemy purely through thought, with no movement whatsoever, and that he can transmute with any part of his body, not merely his hands as with most other alchemists. He has a third eye, hidden in his forehead, which dispatches Greed's incomplete Philosopher's Stone (later drinking it after punishing Greed for his transgressions). In addition, he is apparently capable of violating the law of Equivalent Exchange, as demonstrated when he replaces Al's missing hand without any visible raw material to use - though he may hold extra materials within his body, using them for such transmutations; or is able to bypass the law of natural providence, (transmuting air to metal, etc.).
His body is not that of a human, as shown in a scene where Scar grabs his face and attempts to decompose it, as this ability only works if Scar knows what he is decomposing, and it didn't work on Father, which means that his body is not composed of the elements that form a human body. His third eye and the fact that he can create bodies for the Homunculi out of his own body further support this theory. The full extent and source of his abilities are both unknown. At this point in the manga, his goal appears to be to create an enormous Philosopher's Stone, even larger than the one he used to animate Envy, to use as a passage fee to the Gate. To obtain the stone, he appears to be preparing to sacrifice the entire country of Amestris and the people of various surrounding areas. Once he has the Stone, he will then proceed to open the gate either by performing human transmutation on himself, or by some unknown process possibly relating to his need for "human sacrifices". The entire thought behind this is probably to see the entire "Truth", which would enable him to become a god. He appears to have tried this process in Xerxes, but somehow failed. As a sidenote, his need for "human sacrifices" is completely unknown at this point. Also, there is very likely more to the plan, as Envy has let on several times to characters who have attempted to figure it out.