Argosax was a powerful Demon King who once ruled the Demon World. And serves as the boss of "Mission 18", the final mission of Dante's scenario in Devil May Cry 2.
Argosax The Chaos
Argosax the Despair Embodied
As The Despair Embodied, Argosax appears as an androgynous, horned, angelic being composed of fire, able to change sexes at will.
Pre-Devil May Cry 2
Argosax once was infrequently worshipped by the people of Dumary Island, and it was there that he almost appeared in the Human World, but The Dark Knight Sparda and Vie de Marli defeated him and sealed him away using the four relics known as Arcana.
Arius tries to obtain the Arcana in order to release Argosax, take his power, and become a god. The Arcana are four holy relics used to seal Argosax, and by uniting them at the solar eclipse, a gate to the Demon World will open.
Though Dante manages to interfere with Arius' ritual by replacing the Medaglia with his own double-sided coin, the doorway is still partially opened, and Arius absorbs part of Argosax's power. Because the door is unstable, whoever enters may not be able to return, so Lucia demands to go, claiming she is expendable. However, Dante puts the decision to his coin, and after winning the coin toss, goes in, just like his father once did.
Inside the portal, Dante finds Argosax in its first form, a hideous blob known as Argosax The Chaos. After defeating it a stalk bearing an egg extends from the mass, and Argosax's true form, The Despair Embodied, hatches from it. However, even in this form, Argosax is still brought down by Dante, and is defeated. Afterwards, Dante rides off on a motorcycle, presumably escaping the Demon World through another doorway.
- Argosax is most likely based on the biblical Legion, an entity that was composed of multiple demons possessing a single man in the Gospel of Mark. Both Legion and Argosax are composed of multiple demons and they both possessed a man, which they drove insane.