Dharkon

Dharkon is one of the two main antagonists of Super Smash Bros. Ultimate's World of Light Mode, and is the dark counterpart to Galeem. Dharkon's body consists of many dark purple spiky tentacles formed into a jumbled mass with a single light-blue eyeball in the center.

Dharkon first appears after Galeem's first defeat, emerging from a large crack in the sky, along with an army of Crazy Hands. It proceeds to power through Galeem's Master Hand army and takes control of the remaining fighters, creating its own world of darkness. After its first defeat, Dharkon flees to the final world along with Galeem, who wages a war against Dharkon and its Crazy Hand army with its army of Master Hands. In the final world, if only Galeem is defeated, Dharkon destroys Galeem's army and takes over the world with its darkness, which results in a bad ending. In the other bad ending, where only Dharkon is defeated, the world is completely engulfed in light, and Dharkon's body disintegrates. In the true ending, both Galeem and Dharkon are defeated.

Dharkon uses several attacks during its fights, including creating two large darkness waves that move erratically on the left and ride sides of the screen, which players must dodge. Dharkon may also disappear for a moment and reappear as a single tentacle that moves around the stage as well as create two portals and quickly move between both of them, attempting to damage the player. It also may spawn several bombs that will explode, which have an effect similar to the X Bomb item. It can also spawn dark versions of the fighters, who will fight along with Dharkon, who causes large beams to shoot onto the stage, attempting to damage the player. The only part of Dharkon's body that players can damage is its eyeball, which may temporarily be stunned and fall on the stage, allowing players to get a few easy hits.

During the final battle between both Galeem and Dharkon, Dharkon will attempt to damage players with its tentacles while climbing a vertically scrolling stage. It also spawns more dark versions of the fighters, which players must defeat to progress. Galeem also does this in the second half, except with light versions of fighters.

Similar to how Galeem's name is a corruption of the world "gleam", Dharkon's name is a corruption of the word "darken".

Dharkon also appears as a legend spirit alongside Galeem, which both can be obtained by getting the good ending in World of Light. It is tied with Galeem by having the most overall power of spirits in the game. Though the spirit has no slots, it has a unique ability called "Bane of Light" in which fighters take and deal a doubled amount of damage against fighters controlled by light in Adventure mode.