Brain is a Keyblade wielder who appears in Kingdom Hearts Union χ. He is a member of the Dandelions and was chosen by the Master of Masters to lead a Union after the Keyblade War. 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. This could very strongly imply that Brain is the imposter among the new leaders.
- 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.