The Exile
A pivotal figure in Ishbalan history, the Exile taught Scar's brother the secrets of the Grand Arcanum—Ishbal's indigenous form of alchemy. By the time he shows up in the story, he's living isolated in the southern refugee camp, having been exiled from Ishbal for practicing alchemy against his people's wishes. When Scar stumbles into his hut, he learns his brother trained under this man and immediately wants to know how to create a Philosopher's Stone.
Things get messy when Mustang's forces arrive hunting Scar. The military rounds up Ishbalan refugees to move them to state-run camps, but the Exile's own people actually attack him—forcing the military to separate him from the group for his own safety.
When Ed and Al eventually track him down, he opens up about Ishbalan history. Turns out the Ishbalans were once alchemists themselves, using the Grand Arcanum to reshape what Ishbala had provided them. It was respected work back then, but cultural attitudes shifted. Over time, the practice became taboo—people started seeing it as sacrilege against Ishbala's will. According to him, the only real difference between standard Philosopher's Stone creation and the Ishbalan method comes down to how many human lives you have to transmute into the stone.
By the end of the series, he returns to Ishbal alongside the other refugees to help restore their nation and culture.
Content compiled by AnimeList.moe from publicly available sources.