At first John was planning to help out whoever needed it, but it seemed everyone had things under control. Given the Cactus-Cat armored tail it made sense for his Summon to attack one  of the Needle Blights. "Go for that one covered in needles."  Seconds after being given the order the Ex-Beast sent it's armored branching tail flying at the target.

John meanwhile decided to try and hold the small imp like creature closest to his partner off. Knowing he probably wouldn't do much damage anyway, he simply attempted to grapple it so that his Summon could focus on its fight.