Jack hears Chiaki, but he really really wants that healer to drop. Well, why not both? So, he reaches out with one hand towards Gawain, casting one more Drain, trying to get any bit of health back in the face of the opposing Dragoon's fire attack.

Then he grips his spear again, and sweeps twice in the air, before his spear appears to split, attacking all of their opponents with Chaos Thrust. That is gonna draw a lot of what he has left of energy, but it also increases his physical might, so if he's down to just physical attacks soon, at least they'll be more powerful.