Majhal was an alchemist who showed up in episode four of the anime. He lived in some unnamed town where he was basically the only alchemist around—enough of a big deal that the Homunculi considered him as a candidate to create the Philosopher's Stone. Lust, however, wasn't impressed and wrote him off as an amateur. He worked with an alchemy wristband that had a transmutation circle built into it.
Edward and Alphonse tracked him down while looking for clues about their missing father, having just burned down their own house. While they were there, the town was being terrorized by what looked like a zombie version of a dead villager named Karin, who was kidnapping and murdering girls at night.
Turns out Majhal had been trying to resurrect his dead lover Karin by using the village girls as raw material—he'd transmute their souls into mannequin bodies in her likeness, hoping one would work. When they didn't, he'd destroy the failed attempts before they could escape. He was desperate enough to try the whole thing again and attempted to force Ed and Al to help him out. But Ed dropped a truth bomb: the elderly woman who'd actually been helping Majhal with his plans was Karin herself, just aged. The real story was that Karin never actually died—she'd lost her memory after a wagon accident gave her a bad head injury. Majhal just couldn't recognize her in an old woman's face.
The revelation sent him into a rage. He transmuted a sword and went after Ed, Al, and Karin to kill them all. Ed countered by transforming a rose into a whip, which sent Majhal's sword flying upward. When it came back down, it went straight through his stomach and pinned him to the ground. He died still convinced that his Karin was waiting for him in heaven somewhere.
Content compiled by AnimeList.moe from publicly available sources.