Millicas Gremory

Millicas Gremory is the son of Sirzechs Lucifer and Grayfia Lucifuge, and the nephew of Rias Gremory. Although his father is Lucifer of the Four Great Satans, it is not applied to Millicas, as it is only required for Sirzechs, thus Millicas' family name is Gremory. After Rias, Millicas is next in line as family head.

Appearance
Millicas is a young boy with short crimson red hair and red eyes.

Personality
Millicas is shown to be a well-mannered boy. Despite his young age, Millicas is shown to be very responsible even planning about his future peerage. He also prefers being referred as "Millicas" rather than "Millicas-sama" by the people close to him.

History
Millicas was born a few years before the start of the series.

Birth of the Breast Dragon Emperor
Millicas first appeared in Volume 5 in the Gremory Castle to greet Rias when she returned to the Underworld. He later appeared alongside Issei when they were being tutored about high-class devils and the upper echelons of society and nobility by a private tutor, appointed by Venelana Gremory.

The Heroic Oppai Dragon
In Volume 10, he and his grandmother, Venelena Gremory, are shown to be visiting Issei and Rias after the two of them finished their Oppai Dragon Campaign. Venelena then scolds Rias for her lack of initiative towards her relationship with Issei before asking Issei to reconsider what he should call Rias in private. He and his grandmother then leave the two of them.

In the Volume 13 short story "The Worry of the Next, Next Heir" (which takes place after Volume 12), Millicas goes to the Hyoudou Residence and lives with them. He later has a mock battle against Issei, Kiba, and Gasper. Despite losing to them, his power is extraordinary and his talent is said to be the same as that of Vali by Issei. During his stay, Millicas reveals that he wants to make a team like his father in the future. Later, when Sirzechs asked him whether he likes Satan Red or Oppai Dragon, Millicas chooses Oppai Dragon. This made Sirzechs sad, and it became worse when he sees Issei and Millicas getting along. At the end, Issei calls him Millicas instead of Millicas-sama.

Powers & Abilities
Power of Destruction (滅びの力 Horobi no Chikara): Like Sirzechs and Rias, Millicas also possesses the Power of Destruction inherited from his grandmother. Despite Millicas' young age, he has shown to have better control of his Power of Destruction than Rias, being able to shoot them like a shotgun as well as controlling its direction.

Demonic Power: As the son of Sirzechs Lucifer and Grayfia Lucifuge, Millicas possesses an incredible amount of talent which Issei compares to be at the same level with Vali. The rest of the Occult Research Club also commented that Milicas's control over his demonic powers was beyond what he should be able to do for his age.