Homunculus

For the most part homunculi look human enough to move through society unnoticed, though many share dark hair, purple eyes in the manga, and red nodes tracing their limbs; the 2009 anime gives them varied eye colors instead. Every one but Pride carries the Ouroboros, a mark that simply surfaces on the body at creation like a birthmark rather than a tattoo. Some hide true forms that resemble nothing human. Fueled by the immense energy of a Philosopher's Stone, they do not age and outclass humans in speed, strength and agility. Their signature is regeneration: so long as souls remain in the stone at their core, they knit shut any wound within seconds and rebuild even a shattered body, bleeding and shedding severed limbs that crumble to dust. They are not truly immortal, however, for once that stone runs dry they can be killed.

Beyond the single emotion each one embodies, homunculi tend to feel superior to every living thing, a self-regard born of their innate power, and many carry open contempt for humanity. Envy nurses the most personal, spiteful hatred, while Pride wields the coldest disdain; Greed stands apart as the one who does not truly loathe people, instead craving friends among them because he wants everything life can offer. The 2003 anime deepens this considerably, revealing them late in its run as layered figures capable of love, grief and despair, several of them yearning to become human even as they prey on the human race.

In the manga and 2009 anime the villains trace back to Father, once the Dwarf in the Flask grown from the blood of the slave who would become Van Hohenheim. Seeking to perfect himself, Father split off the seven vices he believed made humans flawed, birthing Pride, Envy, Greed, Sloth, Lust, Gluttony and Wrath from his own purged soul. Using half of Xerxes's population, he made himself a living Philosopher's Stone and gained the means to spawn the others by injecting fragments of that stone into living bodies. A separate method drives a stone straight into a human's bloodstream; most hosts die and the stone is reclaimed, but a strong enough survivor becomes a homunculus. The government later mass-produces soulless Mannequin Soldiers beneath Central Command, mindless white creatures that swarm and devour.

The 2003 anime tells it differently. There a homunculus is born each time an alchemist attempts human transmutation: the intended person never returns, but a malformed being does, keeping the dead one's genetic material and fragments of memory. Feeding on Red Stones reshapes it into a replica of the person it was meant to replace. These creatures serve the schemer Dante, who dangles the promise of humanity to keep them loyal while she manipulates the country toward creating a Philosopher's Stone. Their shared weakness is the remains of their original human self, whose nearness can leave them paralyzed.