Like the other new Union leaders, he was given a book with laws set by Ava. However Brain has declared he wishes to use the book to achieve a personal goal of his, wanting to be the virus that will alter the events set in stone.
Brain has black spiky hair that droops down over his eye. He wears a black coat with rolled up sleeves, gold buttons, and a large collar, grey pants, and black cowboy boots. His face is concealed by a black fedora that sports a black feather with a tan streak down the middle.
During the progress of the chapters, Brain's face was revealed, sharing a close physical resemblance of teenage Master Eraqus.
- In Kingdom Hearts III's secret reports 11-13, an unknown author implied to be Luxu notes that one of the new leaders was an imposter and calls them a 'virus in the program'. Brain later refers to himself with this exact term in a cut scene in Union X. Despite this, it was later revealed the Brain was not the impostor.
- While Brain was originally meant to be union leader, he was not meant to recieve the book of prophecies. Master Ava gave him the book instead along with the original list of new union leaders and the name of who actually was supposed to recieve the book.
- When Lauriam confronts Skuld about his sister, Strelitzia's, disappearence, Brain points out inconsistencies in Lauriam's story as if he is suspicious of him.
- Although Brain later reveals Strelitzia was supposed to be the union leader, he admits he doesn't know what happened to her.