When choosing to continue your game, there are two settings it gives you: Co-Op Settings and Attack Reaction. The description for the Attack Reaction option is as follows:
Partner [will/will not] react to your attacks.
What exactly does this means? By default it seems to be set to No, and the description seems a bit vague. Does that mean if I'm attacking an enemy, my partner will also attack that same enemy? Whatever it does, is there any benefit to using it?