It controls the board, then it uses the frostrider, moorabi, and fire plume harbringer to make the elementals in your hand cheaper. You can also use shudderwock to replay the harbringer’s ability, but try not to play it after you combo out your elementals. Then you play out all of the elementals, then grumble them back, play out fire plume harbringer and replay all of your elementals. This should kill them.