The Dimension Mirror can only be entered if Kirby collects all of the Mirror Shards (obtained by beating the bosses) that resulted from Dark Meta Knight shattering the mirror early in the game; upon entering the mirror, Kirby will immediately be confronted by the dark knight in battle. If Kirby comes out victorious, he will go face-to-face with Dark Mind in several boss fights. After each of these boss fights, Kirby will be transported to a room with puzzles, recovery items, and the Dimension Mirror that will transport him to the next battle; the rooms have themes reminiscent of Radish Ruins, Cabbage Cavern, and Peppermint Palace, respectively. After besting Dark Mind's first form for the final time, Kirby fights Dark Mind in his true form twice more before the fiend is finally vanquished; after Dark Mind's final form is defeated, the mirror is restored to its original glory and the ending plays. Note that Kirby cannot call the Warp Star using the Cell Phone at any point during this stage, although he can call the other 3 Kirbys if he has adequate battery power left. Also of note is that this stage has no map, likely due to its short, highly linear nature compared to the other stages of the game.
|This section contains information that does not coincide with the main series canon.|
The Dimension Mirror also makes a surprise appearance in Kirby: Triple Deluxe’s Dededetour sub-game. After King Dedede defeats Queen Sectonia DX in Royal Road, the Dimension Mirror—now once again corrupted—appears and creates a darker version of the king, known as Shadow Dedede, that promptly engages Dedede in a fierce duel. After Shadow Dedede is quite literally shattered to pieces, Dedede enters the mirror himself and discovers that the mirror was corrupted by Dark Meta Knight, who promptly emerges from the mirror and fights Dedede himself as Dededetour's final boss. Upon his defeat, Dark Meta Knight is sucked back into the Dimension Mirror; to prevent his escape, Dedede shatters the mirror, ending Dededetour.
According to director Shinya Kumazaki, Queen Sectonia's tyrannical personality stemmed from excessive gazing into the Dimension Mirror after Taranza stole it from the Mirror World and gave it to her as tribute.
The Dimension Mirror's inclusion in Dededetour is not canon as the aforementioned sub-game is also non-canon; however, its behind-the-scenes relevance to the rest of the game, such as corrupting Queen Sectonia after Taranza gifted it to her, is still canon. This means that the mirror is not destroyed.