Amadeus Wolfgeist

Amadeus Wolfgeist is the fifth boss encountered in Luigi's Mansion 3. He is encountered and fought on Floor 4 after Luigi locates him in the Great Stage. Defeating Amadeus Wolfgeist rewards Luigi with the elevator button to the sixth floor as well as freeing one of the imprisoned Toads. His name is based on that of composer.

Appearance
Luigi finds an unmanned piano playing, as well as one of the Toads' portraits on the stage. He attempts to get on the stage, but Amadeus Wolfgeist appears and, upon noticing Luigi, briefly gets annoyed at his presence and proceeds to rapidly play the piano to scare Luigi off the stage, smirking once he did so. Upon seeing that Luigi evaded his chair attack, he will express displeasure before resuming playing the piano to summon ballerina Goobs. After the Goobs are defeated, he then completely loses his temper and proceeds to confront Luigi personally by possessing his piano.

Battle
The first phase requires that the player dodge various levitating seats as Amadeus is playing the piano. It is done in sets of three, though in the final portion, all five remaining sets are levitated and thrown.

The second phase requires the player to confront Goobs posing as ballerinas. Two Goobs appear initially. As they are wearing ballet masks, they are initially immune to the flash, requiring that the player knock them off before flashing them and sucking them in. Amadeus Wolfgeist will then summon three more, with the rest of the phase requiring defeating them.

The third phase has Luigi fight Amadeus Wolfgeist himself. He will hop around inside his piano, eventually opening himself up and leaving him vulnerable to a Strobulb flash. Once blinded, Amadeus will move his piano to the stage and launch bombs at Luigi. Luigi must then throw a bomb into the piano lid, causing it to tip over to allow Luigi to use the Suction Shot at it and then forcibly yank it onto the floor; the piano will collapse the third time Luigi does this. After being extracted from the piano, Amadeus will be exposed and try to grab or burn the player, although he can easily be stunned with the Strobulb and then sucked in. He then repossesses the piano and will launch a barrage of piano keys (how many shots depending on how much health he has lost by that point), though he otherwise has the same attack pattern. Once he is defeated, he will formally bow before letting himself be sucked in. Luigi will then retrieve both the sixth floor button as well as freeing the red Toad, with Polterpup activating the steps to allow Luigi up.

Trivia

 * During the third phase, Amadeus's battle is similar to the battle against the Harsh Possessor from Luigi's Mansion: Dark Moon.
 * The behavior is also similar to the Mad Piano from Super Mario 64.