Acabei de assistir à Liga da Justiça: Guerra, mas tenho uma pergunta ...
de Wikipedia :
Because of a brainwashing process being done on him using Darkseid's technology Superman becomes unstable and highly aggressive, resulting in him crushing Desaad to death and attacking anything insight, including other Parademons and Batman. Batman reasons with Superman, helping him reassert his own personality
Como o Super-Homem consegue se livrar da lavagem cerebral?
Este é um filme comum. De tvtropes.org :
Superman, neste caso, é basicamente libertado pelo poder inexplicável, semimágico da força de vontade, assistido por Batman.They know that the loved one is still there somewhere. The hero will win this fight by talking the friend out of the evil influence, usually because of The Power of Friendship or The Power of Love.
Often accompanied by the phrase "I know you are in there somewhere." The hero stalls the fight, trying to snap the friend out of it.
Literalmente não é mostrado no filme, então não podemos saber ao certo.