The potion smacks into the side of Sparks's head, catching him off guard. He's about to yell something at Ramza, when he can feel the effect of the ether kick in and he realized what just happened.

"Y'know, yer lucky I don't need to spend a spell on getting glass shards outta my eye."

He should really pay attention, though, as he looks up in time to skitter out of the way of another laser attack. His eyes go wide as he notices how close he was to getting fried for good, but is back in form fast, casting another Thunder Slash.