He is also known as the Nemean Lion. He is about four to five meters tall and has a jewel on his forehead.
In his human form, he has the appearance of a young boy with spiky dark orange hair, golden eyes, and facial markings.
Regulus is shown to be an observant fighter. He's also extremely loyal to Sairaorg, calling him "Master", and constantly tries to help him by any means necessary.
According to Azazel, Regulus is the Nemean Lion which had been slain by the original Heracles and later sealed by the God from the Bible inside the Longinus Regulus Nemea. After its previous wielder died, Regulus, somehow, materialized himself and killed the group of people that was responsible for his host's murder. It was also at that exact time that Regulus met Sairaorg, who managed to tame him, and then reincarnate him into a Devil worth 7 Pawn Pieces.
Regulus appears in Volume 10, during Rias and Sairaorg's Rating Game. He faced Rias one-on-one and defeated her, telling Issei to use the Phoenix Tears if he wants to save her from retiring from blood loss. He then asked Sairaorg to wear him. While initially refusing, Sairaorg eventually agreed after Issei persuaded him to fight at his full strength. The two of them began to merge, attaining Balance Breaker, before proceeding to fight Issei.
He reappears in Volume 12 alongside his master but did not do anything.
Regulus and the rest of Sairaorg's Peerage helped in the experience day for the Auros Academy built in the Underworld in Volume 17. When Qlippoth launched their attack, he assisted Sairaorg in defending the floating island Agreas. He went into Balance Breaker with Sairaorg and fought against Grendel, alongside Issei. But before he and his master could be overwhelmed by the Dragon, they were sneakily attacked by Walburga, leaving Sairaorg heavily injured from the attack of the Holy Cross user. Grendel used this chance to beat Sairaorg up, but he persevered, and with his and Issei's combined effort, they were able to defeat Grendel and have Koneko Toujou seal his soul inside a jewel from Issei's armor.
In Volume 21, Regulus, having been transformed into Sairaorg's armor, appeared in order to assist Sairaorg in his battle against Bedeze Abaddon for assisting Saji, and to protect his brother and Clan. While the battle initially proved difficult, they managed to overpower and defeat Bedeze when they activated their Breakdown the Beast form. Later, when they heard news of Trihexa clones wrecking havoc in multiple regions simultaneously, all of Sairaorg's peerage assembled, before heading off to reinforce D×D's army who were battling Qlippoth's army in Japan's coastal waters.
Powers & AbilitiesEdit
Demonic Power: As a Devil, Regulus has all the common skills and powers of one.
- Promotion: As a Pawn, Regulus can use promotion to temporarily gain the traits of a Queen, Rook, Knight or Bishop.
Immense Strength: Regulus has an immense amount of power, which is said that upon full mastery, the wielder of his Sacred Gear can split the Earth in half.
Transformation: Regulus has the ability to transform to a young boy who about the same age as Issei.
Flight: Being a Devil, Regulus can use his wings to fly.
- In Greek mythology, the Nemean lion was a monster that terrorized the city of Nemea until it was slain by Heracles.
- Regulus is the name of the brightest star in the Leo constellation.
- Regulus is Latin for 'prince' or 'little king'. Being possessed by Sairaorg references him being a prince and that he comes from the Great King Bael clan.
- In Greek mythology, Regulus was one of the monsters that was raised by Typhon and Echidna, along with Orthrus, Sphinx, Cerberus, Ladon, Hydrea, Eagle, and Chimera.