In the game, he is the leader of the Vanguard as well as being Marta Lualidi's father. After his wife was killed by the Great Tree, Brute creates the Vanguard to overthrow the Church of Martel. At first, he didn't want to be crowned as the king of Sylvarant; however, Richter Abend manipulates him otherwise with Solum's Core and became driven by it's power into a different person.
Throughtout the game, Brute often sent out the Vanguard, including Alice and Decus, to seize Ratatosk's core on Marta's forehead. His plans to destroy the Tethe'allan's was to use the Mana Cannon's power with the aid of the Centurian's core's.
Eventually, he goes as far as to take over Altamria as a Vanguard base. As far as having Regal tied up, he also had Marta confined in another room. After being fought for the second time, Decus took Solum's core and then Brute came back to his senses. While he was recovering from the last battle, he told Emil and Marta that Richter was not to be trusted.
In the end, Brute most likely gets imprisioned for his past crimes.