When Supergirl returns tonight,the Martian Manhunter is forced to make a life-altering decision.
J'onn J'onzz previously promised his father to start main a non-violent existence. So far this season, he's kept his word. J'onn stepped down as head of the DEO. His focus shifted from Supergirl's battles to aiding National City's alien population. However, or when Manchester Black orchestrates a prison demolish and joins a team of supervillains called the Elite,J'onn must re-evaluate his peaceful philosophy in order to stand by his Super Friends and squash this new threat.
Source: blastr.com