Injustice vs Masters of the Universe
He appear following Darkseid after they defeat Zodac.
When the Castle of grayskull is attacked, Mantis appears among Steppenwolf followers and battle all heroes on his way. When Darkseid was defeated, he calls DeSaad to warn him about the situation and to use the Orbital Intimidator to burn everything. When Desaad activated the emergency Boom tube to retreat to Apokalips, Mantis and Granny Goodness was taken.
When they arrive to Apokalips, they realize that Apokalips was burned down by Atrocitus who is now part of the Horde Corps lead by Hordak.