Devilman

Devilman is a multimedia franchise created by Go Nagai. The series protagonist is Akira Fudo, a teenage boy who is possessed by the spirit of the leader of the demons, Amon. Different entries in the franchise play around with this possession, with Akira sometimes left wonder if he was a human with a heart strong enough to overwhelm the power of the demon lord, or if he's actually Amon and just thinks he's still human.

After Akira's possession more demons show up in the world, many of them set on killing Amon either out of a sense of honor or because they aim to take his power. These demons grow in strength as they absorb more humans, although some humans are strong enough to keep their soul and take over the demon's body after an attempted possession. Eventually humanity as a whole learns of the demons and their response is to create a paranoid police state to protect themselves from hidden enemies among them. More innocent people then actual demons are killed by this, including Akira's girlfriend, but it is for naught as eventually humanity is entirely wiped out. In the end all that are left are the humans in demonic bodies lead by the Devilman, and the pure demons lead by Satan. Both sides fight to determine the outcome of the apocalypse.

In the Devilman Lady manga Akira, now residing in Hell, discovers that after his death the entire world was reset so that the demon war never happened. It wasn't even the first time it had happened, as his own world was the result of a reset after the events of Mao Dante. With the help of Jun Fudou, and the opening of a portal from Hell by Ryou Utsugi, Akira is able to return to the earth and teams up with Satan against the true architect of mankind's constant war against the demons: the archangel Michael.

Devilman Oneshots

 * See article: Devilman Oneshots

Jun Fudou

 * See article: Jun Fudou

Miiko
Miiko is a schoolgirl who was possessed by the demon Tollg while masturbating. Her will was strong enough to overcome the demon, but the demon's body occupies her entire torso and can only be hidden under clothing. Akira saved her from an Anti-Demon testing facility and she remained by his side until the apocalypse. She can fire acid from four orifices in her demonic torso.

Psycho Jenny
Psycho Jenny is a powerful psychic demon. She has been able to defeat Devilman several times, and was even able to hypnotize Satan into believing s/he was just a human. In Devilman TV she hypnotized all the children in Tokyo and attempted to make them drown themselves. Devilman intervened and destroyed her with the Devil Beam. Aside from that one time she has never died on screen and potentially was even able to survive the Apocalypse.

Sirene

 * See article: Sirene

Welvath
Welvath is one of the first demons to appear in Devilman, possessing one of the partiers at Asuka's sabath. She is also the first demon to be killed by Devilman.