Santa staggers under the Chaotic Wave's assault. He could see how in alternate histories, they could've died here. But that's not an option here. He's getting this done no matter what it takes.

He's got the power of an Overlord. With dark-spells temporarily powered down, that limits his arsenal to a single spell. That's fine. He's really been wanting to use this one.

He lifts his fingers and points them at Garland to deliver his force Lightning Storm. Even if it doesn't get through his defenses, it might distract the big guy from his housemate's summoning.