Stop the Knightmare

E-Boss: Stop the Knightmare is the second to last main mission in Luigi's Mansion: Dark Moon. This is a Boss-Mission, where Luigi must defeat the Tough Possessor, in order to get the final piece on the Dark Moon.

Plot
After having a short chat with E. Gadd, Luigi is pixelated to the Terrace to get the last Dark Moon piece, Luigi is warped into the Paranormal Portal created by King Boo in the last mission.

Luigi ends up in a room with several suits of armor, one having the Dark Moon piece on it, Luigi attempts to get the piece right before the Tough Possessor scares Luigi, and tries to destroy Luigi by using the suits of armor in the room by cloning itself.

To defeat the Possessor, Luigi needs to trip all the armor on carpets to make them fall, causing the possessor's to combine into one and bash a wall, once two skins are removed, he and the clones make a giant suit of armor in order to crush Luigi.

To defeat the giant suit of armor, Luigi has to make sure both feet are on two carpets and lift them both, but this requires good timing. Once done, Luigi can defeat the Possessor and get the piece.

Luigi then gets a call on the Dual Scream from Gadd, who tells him to come back, but when Luigi is being pixelated back to the Bunker, he is warped back to the portal, only the piece remains, making E. Gadd horrified.

Trivia

 * Upon completing this mission for the first time, the game will immediately take Luigi to the next mission to face King Boo, without being pixelated back to the Bunker. If the player completes this mission again after beating the game, Luigi will be pixelated back to the Bunker where E. Gadd will remark how Luigi wanted to fight the Tough Possessor again for the "adrenaline rush".