The other Diamonds were furious. In a last-ditch attempt to wipe out the Rebellion, the Diamonds launched a direct attack against Earth, and in their fury, they used their powers to end the fighting once and for all.
|—Garnet in "Your Mother and Mine"|
The Corrupting Light was a cataclysmic event and final assault against the Crystal Gems by the remaining members of the Great Diamond Authority. The attack was intended to obliterate all Gems on Earth; however, it instead resulted in the corruption of almost every Gem on the planet. This attack marked the end of the Rebellion.
While intended to only be used against the Crystal Gems, some Homeworld Gems, such as Nephrite and her crew, were also caught in the crossfire because they were stranded on Earth when it was unleashed.
The light was first shown in "Same Old World" and later seen in the episode "Monster Reunion" in greater detail. The light is composed of blue, white, and yellow rays, the colors of the three current Diamonds.
Given Yellow Diamond's ability to disrupt Gem bodies, Blue Diamond's ability to overwrite Gem emotions and White Diamond's ability to overpower Gem minds, the Corrupting Light's effect may represent a combination of the worst parts of their abilities - warped bodies, broken minds, and rampant emotions.
4,500 Years Ago
At the end of the Rebellion, the Diamonds faced two massive losses: the "destruction" of one of their own (Pink Diamond) and the loss of her colony, Earth. In retaliation, the Diamonds combined their powers and launched a direct attack against Earth: the Corrupting Light.
Before the Diamonds attacked, Homeworld Gems were ordered to leave the planet by one or more of their commanders. This caused a panic in which Gems fled the planet en masse in both spaceships and through the Galaxy Warp to Homeworld. In this commotion, Lapis Lazuli, who was in the mirror containing her, was dropped and stepped on, cracking her gemstone. Being poofed and trapped inside the mirror, she was saved from being corrupted.
After the majority of Homeworld Gems had fled, a light appeared in the sky, accompanied by what Steven interprets as "A sound? A song?". Later, in "Monster Reunion", the purpose of the light is explained by Centipeetle. It is confirmed to be the source of her corruption. It was most likely to ensure the Rebellion could never threaten Homeworld again. Based on her recollection of the event, it seems that the majority of Gems were not aware of what exactly they were fleeing from, as she was kept in the dark by her commander.
Greg Universe explained to Steven in “The Return” about the Rebellion, and that “in the end, [Rose] could only save a handful of her closest friends. If it weren’t for her shield… man, I don’t know.” The Corrupting Light is the context for this quote, a catastrophe that ended the Rebellion and eliminated the rest of the surviving Crystal Gems up until the Diamonds healed the damage together at the end of Change Your Mind.
- The song in question, in addition to appearing in "Same Old World" and "Monster Reunion", has also been heard as a motif at the beginning of "Blue Diamond", "Yellow Diamond", "White Diamond".
- The degree of the light and song's direct role in inducing corruption, or if they were merely byproducts of something else, is unknown.
- It's possible that the light attack was actually the manifestation of an occurrence in theoretical astrophysics known as a kugelblitz, which is a concentration of heat, light or radiation (in this case being light) so great in intensity that it traps itself in its own event horizon, warping spacetime around it. This would be a possible explanation in and itself as to why Gems exposed to it became corrupted; since physical forms of Gems are made of light, they were likely warped by the physics-altering nature of the kugelblitz.
- The mental corruption caused by this light is referred to as "damage from the Diamonds" in "Monster Reunion" by both Pearl and Steven.
- In order for a Gem to become corrupted, their physical form needed to be exposed to the light itself. As a result, the following Gems were on Earth during the attack, but were not corrupted for various reasons:
- It is revealed in "Legs From Here to Homeworld" that the Diamonds' attack wasn't intended to corrupt all Gems on Earth but destroy them outright, showing that at least Blue and Yellow Diamond were unaware of its effects. However, Pink Diamond's absence from the combined attack prevented the blast from hitting them at its fullest possible strength, similarly to how White Diamond's absence prevented Yellow Diamond, Blue Diamond, and Steven from permanently undoing its effects.
|Cultural||Beach City or Bust • Beach City Underground Wrestling • Beach-a-Palooza • Boardwalk Parade • DelmarvaCon|
|Historical||Corrupting Light • The Rebellion|