The Thunderhand is mainly used to light up Blue Orbs in the game. The Thunderhand can also do Critical damage to fire-based enemies such as red Piranha Plants. In battle, Luigi can utilize Thunder Bros. with Mario which has a chance to lower the defense of enemies and even bosses. Also outside of battle, after learning it from Gigi and Merri, Luigi can use the Thunderhand on Mario to cling themselves together allowing them to move at exactly the same time. It is helpful for crossing narrow passageways with hazards around.