Keeping in melee range with the monster isn't stopping it from attacking his allies, like Jack had hoped. Why can so many monsters cast magic? Chiaki would have some answer about power levels, undoubtedly.

The Rex roars and adjusts his angle to snap his jaws down at Jack. He raises an arm, and the teeth scrape across his arm-guard, one punctures through the metal. Jack retaliates with a deep thrust of his sword back, no time to amplify the attack with magic, but he gets a partial heal from the Crystal Knight ability. The beast is snarling, blade-like teeth barely inches from Jack's face, but Jack's own lip curls in an aggressive snark right back. No. He's got this.