Satan

Satan is one of the Seven Deadly Sins.

Appearance
As he/she has not appeared in the series as of yet, nothing is known of what he/she looks like at this time.

Personality
As he/she has not appeared in the series as of yet, nothing is known about his/her personality.

History
Before the Demon World was united under Beelzebub III, Satan was a king/queen of one of the countries within it. In addition, the Solomon Company managed at some point to gain control over him/her, despite his/her great power and reputation.

Powers & Abilities
As one of the Seven Deadly Sins, Satan has great power, and is stated to be on the same level as the Great Demon Lord, Beelzebub III.

Trivia

 * Satan, in the Abrahamic religions, is the personification of evil and temptation, often described as an angel who fell out of favor with God.