Michael

Michael is the former leader of the Angels and Seraphs. He was the previous Archangel before Gabriel took over and one of the God of the Bible's creation's, who took His place as leader after He died in the Great War. His current goals were to recreate the lost members of Heaven (mainly the Seraphim) and guide the Church with God's teachings.

Appearance
Being one of the very first creation of Angels in existence, Michael is around 10,000 years old with the appearance of a handsome-looking man with long blond hair and green eyes. Like Azazel, he has twelve wings growing from his back, and unlike other Angels whose wings are white, his wings are colored gold, further symbolizing his position as the former leader.

In the anime, his eyes are shaped in a perpetually sad manner even when genuinely angered or happy.

Personality
As leader of the Angels, Michael in his few appearances has shown to be extremely kind and compassionate. However, he will put the good of the many above the good of the few, as shown when he allowed Asia to be banished in order to preserve the religious faith of the Christian people and not risk the safety of Heaven. Michael is extremely loyal to his creator the God of the Bible. After his death, Michael did everything he could to maintain the religion of Christianity, leading the Angels and guiding the Church. He is even willing to be allied with the Angel's former enemies of Fallen Angels and Devils to ensure the Angels survival as a species.

Despite being an Angel, Michael lacks any of the prejudice and racism that a lot of Angels bear towards Devils and Fallen Angels due to his immense kindness, and is perfectly willing to show kindness to or even befriend them. This is shown in his first interaction with Issei, where he showed courtesy and politeness.

Despite his kindness, Michael can be merciless towards evil people like Rizevim as shown when Michael outright stated to Rizevim he will show no mercy.

History
One of the first creation and right-hand man of the Biblical God, Michael served as the leader of the Angels and assisted the Biblical God in the Great War against the Devils and Fallen Angels. After God died in the Great War, the Angels were forced to retreat as Michael and the other Seraphs try to activate the Heavens' system and were successful in activating it with Michael as the center as he takes over the place of his creator as the supervisor of the Heavens' system.

Birth of the Breast Dragon Emperor
He appears in Volume 4 of the light novels to give Issei the Holy Sword Ascalon, the Dragon Slayer sword that was wielded by St. George. He later agrees to the signing of the treaty between the Three Factions, as all three can no longer afford another Great War along with a bigger threat in the terrorist organization Khaos Brigade. In a magnanimous gesture of kindness, he accepts Issei's request to allow Asia and Xenovia to pray to God without pain, in spite of them being devils and therefore racial enemies to Heaven and Angels.

Sometime after the creation of the Brave Saints system, Michael angelized both Irina Shidou and Dulio Gesualdo as his Ace and Joker.

In Volume 6, Michael sent Irina to Kuoh Academy as the Angels' representative.

The Heroic Oppai Dragon
In Volume 12, Michael initially intended to enter the Greek Realm of the Dead with Azazel and Sirzechs Lucifer to confront Hades, the God of the Greek Realm of the Dead, for breaking the treaty but was stopped by Azazel, stating that it would be bad for the Archangel to be in the Underworld. Michael, however, still sent his Joker, Dulio, to accompany them.

The Legend of Oppai Dragon and his Lively Companions
Michael is mentioned in Volume 16, approving of Irina having a relationship with Issei and searching for a method to make it happen without having her fall.

In Volume 18, Touji Shidou, Irina's father, under Michael's order reveals the creation of a special room, that allows an intimate relationship between a Devil and Angel. Later he invites the Gremory team to the Heaven, to discuss about the incident of Exorcists being killed one after another.

Powers & Abilities
Immense Strength: As the former leader of the Seraphs and Angels, and the only Archangel along with being the only Angel with twelve golden wings, Michael is the strongest Angel and likely wields power equivalent to a Satan-Class Devil.

Holy System Control: Michael's true power, however, comes from the fact that he is now the one in control of the system created by God in the distant past, which is what causes harm to Devils who come into contact with blessed objects, provides miracles, and determines who can be saved. Unfortunately, with Michael in charge, the system is vastly inferior to how it was with God running it.

Master Magician: Michael has expert knowledge when it comes to various kind of magic spells common to those of holy and angelic magics and rune symbols. He can create very powerful barriers that protect the DxD [Team].

Immense Light Projection: Being an Angel, Michael is able to form various weapons and attacks from light. Michael's ability in creating and using weapons of Light is vastly superior to regular Angels, able to quickly create a gigantic spear of light as shown when he attacked Rizevim.

Flight: Being an Angel, Michael can use his twelve golden wings to fly.

Trivia

 * Michael's suit in the Brave Saints system is the Suit of Spades ♠.
 * Michael's name means "who is like God?". This is a rhetorical question, implying no person is like God.