Water Blast

From the Super Mario Wiki

Water Blast, is an attack used by the bosses Yaridovich and Czar Dragon in Super Mario RPG: Legend of the Seven Stars. Despite its name, Water Blast is actually an Earth and not a Water attack, most likly because the attack disrupts the earth. It is also mastered by Culex's Earth Crystal. Water Blast deals medium/high damage to all party members. When used, Water Blast will cause spouts of water to appear everywhere on screen with steam rising upwards, followed by a giant explosion.