Zack can handle this on his own, because he's done it before, fought these creatures before -- singly, and when joined to the man behind him. He's done it before and he's doing it again, determined to protect two people he cares for. And perhaps it's telling that Martel has so easily fallen into that category, someone Zack would not hesitate to put himself at risk for.

But there's little enough time to think about that, time better spent in handling the four creatures coming quickly to their senses. The Ahriman falls quickly, and the Hound and Sahagin are smart enough to rush him together. And he can handle that too, but the Griffin is the strongest of the four, and he can't reach it in time--

Bzzzt! The flash of the Materia Zack keeps in his sword's slots, and a bolt leaps out for and strike at his three foes. He's got another slash before the spell even fizzles, never one to trust entirely in casting to fell his foes.