Sairaorg Bael

Sairaorg Bael Born as the eldest son of the Bael Clan, Sairaorg did not inherit the Bael's trademark Power of Destruction that Rias and Sirzech's inherited from their mother, who came from the Bael Clan. Because of this, his younger half-brother was appointed to be the next heir of the Bael Clan. His mother told him to become strong in different ways. Sairaorg trained his body to its limits to become powerful and due to this, he defeated his younger half-brother, which made him the next heir of the Bael Clan. After his defeat, the younger half-brother now plans on assassinating Sairaorg. Sairaorg desires to become Satan to prove himself even with his lack of special demonic powers.

Appearance
Sairaorg is a handsome young man with black hair and violet eyes. He is very tall and has a muscular build due to the extreme training he has done

Personality
Sairaorg has a noble and calm personality and greatly respects his opponents. He also likes to fight strong people, to the point that Rias Gremory, his own cousin, called him a battle maniac. He is shown to be a kindhearted and compassionate person and has a very straightforward personality.

Plot
Birth of the Breast Dragon Emperor

Sairoarg appears in Volume 5 as one of the six young Devils chosen for the Young Devils Gathering and stopped Seekvaira Agares and Zephyrdor Glasya-Labolas who were arguing, knocking Zephyrdor out and convincing Seekvaira to stand down. He later faces Zephyrdor in a Rating Game which he and his team overpowered Zephydor's team and won by dominating and crushing Zephydor's will to fight.

He reappears in Volume 6 alongside his Queen, Kuisha Abaddon, after finishing his interview on the television at the Underworld for the Young Devils Gathering, greeting Rias and her peerage who were on their way for the same interview and leaving after telling Rias that he wants to fight them with pure power only.

The Heroic Oppai Dragon

In Volume 9, he has a sparring match with Issei while his hands and legs are on a heavy seal. Near the end of Volume 9, he is seen talking with Seekvaira who was complaining about Issei's new powers and that the current Satans favor him but Sairaorg, who was pleased by the event, ignored her.

In Volume 10, Sairaorg faces Rias in their Rating Game, during which he eliminated Yuuto Kiba, Xenovia, and Rossweisse in the games, facing Issei in the final round. While initially refusing to use the Balance Breaker of his Longinus, Regulus Nemea, he eventually used it after persuasion from Issei. In his Balance Breaker form, Sairaorg's strength and speed increased greatly to the point where he easily shattered Issei's Scale Mail while in Rook mode. Despite this, he ultimately lost to Issei after the latter manages to achieve his Cardinal Crimson Promotion in their battle, fighting Sairaorg in a fist fight which Sairaorg lost after losing consciousness.

In Volume 12, Sairaorg goes to the Gremory territory to check on Rias and is the one responsible for helping her regain her composure after Issei's "death". He later fought against Heracles and easily defeated him. He and the Gremory Team then welcome Issei who came back from the Dimensional Gap, witnessing Vali Lucifer and Pluto's fight, which Vali won dominantly as Issei and Cao Cao fight one-on-one in a rematch. After Issei defeats Cao Cao, Sairaorg proclaims that he shall be the one to defeat Issei.

The Legend of Oppai Dragon and his Lively Companions

In Volume 16, Sairaorg participated in the meeting for the formation of D×D and agreed to join the team to fight against Rizevim Livan Lucifer and Qlippoth.

Sairaorg and his peerage helped in the experience day for the Auros Academy built in the Underworld in Volume 17. When Qlippoth launched their attack, Sairaorg and his peerage first defended the floating island Agreas then helped in the defense of Auros after the appeareance of the legendary Evil Dragons Grendel and Ladon. He and Issei engaged in a fight against Grendel and was able to overwhelm him before Walburga sneakily attacked Sairaorg. Even with the increased defense because of Regulus Nemea's Balance Breaker, Sairaorg was still 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.