Brain

Blaine is the leader of the the Oracion Seis guild, a dark guild composed of highly powerful mages whose goal is to find a very destructive power known as Nirvana that was sealed away long ago. Not much is known about him though he has a habit of calling his opponents "trash" or "maggots".

Oracion Seis arc
In the battle with the alliance consisting of Fairy Tail, Blue Pegasus, Lamia Scale and Cat Shelter. He doesn't take part, allowing the others to deal with them. Once their opponents have been defeated he goes to finish it with a spell called Dark Rando, gathering a mass of dark energy above him through his staff. Before he can fire it though, he spots Wendy and suddenly hesitates. Implying that, like Natsu Dragonil, he seen her before.

After he gets over his shock, Blaine proceeds to kidnap her (and Happy unintentionally since Wendy grabbed him as she was being taken) and depart the battlefield, firing the intended spell at the other defeated members to finish them off. Though unknown to him, Jura Nekis had saved the alliance at the last second. Blaine then takes Wendy and Happy back to the Oracion Seis's base and informs the other Oracion Seis members of Wendy's healing magic. He then has Racer bring in a coffin while the others continue to look for Nirvana. After Racer does so, he opens it and reveals Gerard inside. Blaine then explains to Wendy that he wishes for her to revive him since he could easily lead the way to Nirvana (as Gerard was in the Magic Council and thus knows it location from them) and that Wendy, who oddly enough knows Jeral, owes a debt to him as well. When Wendy hesitates, Blaine grants her five minutes to make her decision. Ultimately she chooses to revive Gerard much to Blaine's delight. However no sooner then Gerard recovered, he turns on Blaine and knocks him to the lower levels of the hideout before leaving. Angered at this and beveling Gerard trying to take Nirvana for himself, he has Cobra track down Gerard hoping he'll lead the Oracion Seis to what they seek.

After Racer kills himself, Blaine in anger awakens Midnight to kill the Light Team.

Magic
Blaine apparently uses dark magic but he hasn't been seen using more than one spell.