Elma
She's the main character's little sister.
Her body is frail.
She's always obediently staying in their castle
.
She loves to refer to her brother as Onii-sama. And would like to be of help to him.
Her older sister Fegor is helping their brother with the super overpowered magic that she wields.
Elma looks up to her older sister a lot.
Fegor
Fegor is Zeablos’ older sister, who represents sloth of the seven deadly sins, and the demon Belphegor. She also calls her brother “Zea-chin”.
While she doesn’t speak much, she cares deeply for her brother, and has accepted the challenge against Trillion. She’s rather lazy and always likes to sleep around, but she is said to have tremendous magical powers.
Main character refers to her as Aneue.
Lucie
Lucie is Zeablos’ niece, and is the demon lord who represents pride and the arrogance of Lucifer. She seems to look down on Zeablos for having been defeated at the hands of Trillion, and has decided that she’ll take him on herself to become the next great demon lord.
She was brought up with special education for the gifted, and has the pride to go with it. Lucie is very spoiled and a high-handed girl. She is also PelPel’s older sister.
PelPel
PelPel is another one of Zeablos’ nieces, and her sin is gluttony, derived from the demon Beelzebub. She’s Lucie’s innocent, lighthearted and somewhat foolish sister.
She joins in on the fight against Trillion so that she can become a great demon lord to follow her dream of turning the underworld into a giant candy kingdom. She’s always been fond of Zeablos since she was little, because he would always give her sweets.
Mammon
Mammon is Zeablos’ cousin, who represents the sin of greed and the demon by the same name, Mammon. She has a bit of an open-hearted personality, and tends to wander off doing whatever she feels like.
She decided to help Zeablos so she could become a great demon lord and gain all the riches of the underworld. She was originally in charge of guarding a certain gate of hell, but decided to go treasure hunting instead.
Asmedia
Asmedia is Zeablos’ cousin who represents the sin of lust, and the demon Asmodeus. She calls Zeablos “little boy” and loves to show off her sex appeal.
She has a special tendency that involves witnessing the catharsis of the enemies that die before her, and due to her desire to see what she would get from the death of Trillion, she decided to join.
Levia
Levia is Zeablos’ childhood friend who represents envy or the jealousy of Leviathan. She puts on a mature demeanor by calling Zeablos “Great Demon Lord-sama” around others, but she shows a much sweeter side when she’s alone with him.
She resents Trillion for having taken Zeablos’ life once, as she cares about him more than anything. A little too much, as she gets pretty hostile towards others when they seem to be having a fun chat with Zeablos.
Faust
A girl with the power of the "Grimoire Misaotamashi",she saved Zeablo
In exchange for the force to overthrow trillion, she made Zeablo sign a contract to take over her soul,
Zeablo
Voiced main character
Astaroth
Apparently he's main character's older brother.
He's Lucie and PelPel's father
He has a cute dog and is the big shot ruling over the castle.
Kerberos
Elma and Astaroth's pet doggie.
Trillion
Final boss. Has a mouth on his belly like PelPel and claws like Fegor
