Luckily, the creature had come up close enough to the body of water that Kai had drawn off of to take down the Imps earlier when he went running off. 
He took a knee to conserve energy and help him concentrate as he drew up on his power and the pond several feet away. It swept across the ground in a river, snaking around people's feet so it didn't get his classmates wet but went right to the creature, soaking the ground underneath it in a tight pool so no one else would be in the water when Seth went to zap the water to electrify it.