Demon

A Demon Lord Digimon that leads the many Devil and Fallen Angel Digimon. Like Devimon, Demon was originally an Angel Digimon, and a particularly high-ranking one. However, because it raged in fury or rebellion, against a being of goodness in the Digital World (perhaps the very human that created the Digital World), it was deleted to the Dark Area (the graveyard of deleted data). It has vowed to one day conquer the Digital World, in revenge against the being of goodness. Also, it is plotting to secretly revive the "Super Ultimate Digimon," who led the rebellion and was the strongest among the Ultimates.

(Source: Wikimon)