Gwalark can lead an assasination charge against a damaged enemy summoner. When chasing a summoner for the kill, Gwalark provides inescapable reach.
By far the weakest of the Breakers' trio of champions, you should only summon Gwalark in very opportune situations as his stats for his cost are poor and if his abilities don’t add any value to your situation, you are better off spending your magic on something else.
However, Wind Archers that fly over everything at 4 spaces are incredibly scary for a damaged enemy summoner!