Fullmetal Alchemist: Brotherhood - episode 62 - 19 Jun, 2010

Hohenheim and the others stop Father from making more philosopher's stones, but as Edward rejoins them, Father spawns humans resembling the people of Xerxes before attacking with a powerful blast which takes out half the headquarters. They barely manage to survive the blast, but Alphonse and Hohenheim take some heavy damage protecting the others. Before Father can kill Edward and Izumi, the Briggs Fortress soldiers, along with several of Edward's allies, join up to attack Father and use up his stone supply. Father lets down his barrier temporarily to try to absorb Greed's stone, giving Edward, Armstrong, and Izumi the opportunity to damage him to the point of defending himself manually. As Father starts to lose control, he creates a blast which traps Edward's arm while his automail arm is destroyed. With Edward in danger, Alphonse convinces May to help him perform a transmutation, trading his soul for the return of Edward's right arm. Alphonse rejoins with his body on the other side and with his arm returned, Edward frees himself to unleash a series of blows on Father. (Source: Wikipedia)