Dark Emperor

The Dark Emperor (, King of All Darkness) is a boss from the universe.

Origin
The Dark Emperor is the final boss of the Secret Quest of Find Mii II (also known as StreetPass Quest II in PAL regions) in the pre-downloaded Nintendo 3DS application StreetPass Mii Plaza. A glowing bird-dragonlike hybrid, he is the differently colored and more powerful version of the Dark Lord from the Normal Quest, and his goal is to "swallow up all the light in the world and plunge (the world) into darkness". He appears at the top of the Castle of Darkness - Roof level as the third and last boss, grabbing the player's royal Mii after the Armored Archfiend and Ultimate Ghost (the final boss from the original Find Mii) are defeated.

At the start of the battle, the Dark Emperor spews level-down gas to weaken the player's party of Mii heroes (this can be undone with a Dispelling Draft from the potion service). Defeating the Dark Emperor finally frees the player's royal Mii and rewards the player with a treasure chest containing an accessory and/or golden key.

As a stage hazard
The Dark Emperor appears as a stage hazard on the Find Mii stage, and uses magic to increase or decrease a player's attack, defense, special attack, speed, or all four aforementioned stats. Red magic increases stats while blue magic decreases stats. The Dark Emperor can also use purple magic to cause an earthquake that temporarily destroys either of the two platforms of the stage.

The Dark Emperor will occasionally fly into the foreground, causing collision damage to nearby fighters and attacking with his roars. While the Dark Emperor deals minor contact damage, colliding with the Dark Emperor when he flies into the foreground or while he roars deals high knockback, making him dangerous near the sides of the stage. However, he can be defeated, which stuns him and grants stat boosts to whoever lands the final blow. After defeat, he will fly back into the background before respawning after a period of time.

As a stage hazard
The Dark Emperor returns as a stage hazard in Super Smash Bros. Ultimate, functioning the same as in for 3DS, with the exception of his stat boosts being picked at random instead of choosing based on the color of each fighters' costumes.

Spirit
The Dark Emperor also appears as a Legend-class primary spirit.

In Adventure Mode: World of Light, the Dark Emperor is presumably one of the countless spirits captured by Galeem during his takeover of the universe. After Galeem's defeat, Dharkon takes control of Galeem's spirits, including the Dark Emperor. The Dark Emperor's spirit is located in the Sacred Land sub-dungeon of The Dark Realm.

The Dark Emperor uses a Giant puppet fighter and is fought on the Find Mii stage. During the battle, the Dark Emperor appears as a stage element while Ridley is equipped with super armor, referencing how the Dark Emperor cannot be flinched when attacked as a stage boss.

The Dark Emperor can be summoned using the cores of, , and.

Trivia

 * The Dark Emperor ignores the intangibility granted by several Final Smashes, allowing him to interrupt the user and cause them to lose the Final Smash. Examples include 's Ancient Bow and Arrow, 's Dark Pit Staff, 's Critical Hit, and even  or 's Critical Hit dashes.

Rey de las Sombras