Isaac McDougal

A cloak of drab, unremarkable cloth lets Isaac slip through Central unnoticed, but beneath it he keeps the old State Alchemist uniform he never truly abandoned, its right sleeve ripped away and a long panel of fabric trailing down the back. His black hair is bound back save for a single loose lock that falls across his brow. Looking to be somewhere in his thirties, he carries a broad, heavily built frame and stands well above Alphonse Elric, though Alex Louis Armstrong still towers over him.

Blunt and short-tempered, Isaac speaks with the hard edge of a man carrying knowledge no one else seems willing to face. His years in the Ishval conflict and a grim discovery made while underground appear to have left lasting scars. He frames himself as a savior, certain that exposing the military's secrets is worth any cost, and he cuts down soldiers without flinching when they block his path.

Beneath that conviction runs a streak of instability. He mocks the Elric brothers on learning they attempted the forbidden art, cackles when his ice briefly swallows Central Command, and moves to strike down the Führer with no trace of hesitation, revealing just how reckless his crusade has become.

Isaac earned his commission as a State Alchemist and fought in the Ishvalan campaign, then surrendered his certification and walked away from the army once the fighting ended. Vanishing into hiding, he threw in with an anti-establishment faction opposed to the Amestrian regime.

His specialty is the control of water, which his title only half describes. He can freeze any source of moisture, shaping ice into footpaths, crude blades, or barriers, and as a last resort he can even solidify his own blood into a weapon. By laying a hand on a victim he can flash-freeze or boil the fluid inside their body to kill in an instant, though the trick fails against Edward's automail rather than flesh. He keeps his transmutation circle both etched onto a gauntlet and inked into his palm for instant access.

Returning to Central, he kills several soldiers and raises a mass of ice before the Elric brothers subdue and cuff him, only for him to escape by boiling a puddle into a screen of steam. An attempt to recruit the imprisoned Solf J. Kimblee goes nowhere, and a brush with Roy Mustang ends when he douses the colonel and slips away. His masterstroke is a ring of transmutation circles seeded across the city that spawns a seemingly endless wall of ice; not even Mustang's flames can check it, and only shattering the circles can stop it. The Elrics and Alex Louis Armstrong finally corner him, and when close combat leaves him badly hurt, he flings his frozen blood as a distraction while demanding whether any of them grasp what their nation has become, a hint that he had glimpsed the truth beneath Amestris. Fleeing down an alley, he runs straight into King Bradley, whose blade ends him. Later episodes revisit him, and Edward comes to regret dismissing a man who had seen the danger first.