Galeem (キーラ, Kiira) is one of the two main antagonists of Super Smash Bros. Ultimate's Adventure Mode: World of Light. He is described as "Lord of Light" and the "ultimate enemy" in the World of Light. His goal is to recreate the universe in his own image. His dark counterpart is named Dharkon.
Role in World of Light
Galeem is first seen accompanied by an army of Master Hands, approaching the cliff where the fighters are situated. As the fighters prepare for battle, every Master Hand surrounding Galeem slowly disintegrates into a glowing, blue streak of light that ends up being absorbed by the winged being. As the fighters prepare for the god-like being's next move, Shulk suddenly envisions the downfall of his comrades at Galeem's hands and immediately looks at them all in shock and despair, but perhaps foresees Kirby's escape. The singularity between Galeem and the now-absorbed life force of his Master Hand army creates a black hole, which soon collapses, unleashing an array of beams of intense light. He uses this attack to not only vaporize every fighter that was situated on the cliff (with the sole exception of Kirby, who just barely manages to escape the onslaught with the help of his Warp Star), but he also uses the aforementioned beams of light to atomize every non-playable character, leaving them as nothing more than spirits.
From this point onward, the planet in its entirety becomes engulfed by Galeem's light, with said light slowly expanding throughout the galaxy, engulfing and vaporizing multiple planets. Eventually, the deadly light produced by the deity-like being erases the entire universe, leaving nothing in its wake. The planet on which the ordeal started is now left as nothing more than a barren wasteland, with its remains currently inhabited by the now-hostile souls of non-playable characters. Kirby, who has ended up becoming the sole survivor of Galeem's onslaught upon the universe, makes a rough emergency landing into a nearby canyon. As he recovers from his crash-landing, he looks towards a vast landscape consisting of various areas, some of which are recognizable as coming from the fighters' old worlds. The landscape, constructed by Galeem, is none other than the World of Light.
Shortly afterward, it is also revealed that Galeem is the creator of the puppet fighters, who are unleashed upon Galeem's new world with the purpose of stopping Kirby from freeing his comrades. After Galeem's first defeat, Dharkon appears along with his army of Crazy Hands, driving Galeem away. Galeem later returns when Dharkon is defeated and flees into a dark portal, with Galeem in pursuit.
In the final world, Galeem wages war with Dharkon, while also seeking to destroy the fighters. If only Dharkon is defeated, Galeem destroys Dharkon's army and strikes him down, killing him by engulfing the world in light, resulting in one of two bad endings. The true ending can be obtained by defeating both Galeem and Dharkon. Both Galeem and Dharkon are finally defeated by the fighters, sinking into the ocean and exploding thereafter.
Galeem's core is the only place it can be damaged. He can be stunned, which drops the core on the stage for several seconds. Once his health drops below half, Galeem's core will constantly emit a bright shine.
Note that many attacks' characteristics, such as number of projectiles fired, vary depending on both Galeem's health and which battle it is. Also, certain attacks are never used in certain battles.
During the final battle with Galeem and Dharkon, both bosses will deliberately target the player. However, owing to their status as mortal enemies, they can also damage each other; if one is stunned, the other will seize the opportunity to take a potshot. Regardless, only the player can deal the final blow.
Note: All numbers are listed as if the player is not using Spirits or Adventure Skills and is in the second or final battle. Galeem deals roughly ×0.848 damage in the first battle.