Disclaimer: FMA belongs to Arakawa Hiromu
Twenty-two: God
Roy Mustang was a scientist, not some religious person. He didn't believe in some being watching over the whole human race, waiting for them to make a mistake.
When he was forced to kill people with his work and his research, engulfing them in flames that took so long to take life (he could still hear their screams at night), he cried up to the heavens, asking whatever thing people believed was there if this was its idea of justice. The soldiers around him gave pitiful glances to the alchemist raging against God only to receive no reply, but they didn't feel it as he did – when he sent out his sorrow and anguish in his words, they echoed back, pulsating and alive, and he couldn't speak for the fear that he had been wrong all along.