Leviathan

Leviathan 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, Leviathan 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, Leviathan has great power, and is stated to be on the same level as the Great Demon Lord, Beelzebub III.