DC reveals the wildest and potentially most powerful type of Kryptonite, linking Superman to one of his lifelong villains. Green is the most famous of all Kryptonite colors in Superman lore, but DC has recently shined a light on other types. Superman learned to control Red Kryptonite’s rage in DC’s prime continuity, while Superman: The Kryptonite Spectrum has introduced and redefined other colors.

Purple Kryptonite time-shifts Superman, Cobalt Kryptonite turns Supes into a kaiju, and Speckled Kryptonite de-ages him into Superboy. These new colors join Green and Red, as well as the brain-splitting Black and the power-negating Gold. While some of these types are both incredibly useful or dangerous, none of them compare to DC’s newest Kryptonite.

To revert Cobalt Kryptonite’s de-aging effects, Batman gives Superman a liquid dose of Rainbow Kryptonite, which brings the Kryptonian’s body back to normal but grants him mind-blowing side effects.

Batman Tests Rainbow Kryptonite On Superman, To Unexpected Results

Superman: The Kryptonite Spectrum #3; Written by W. Maxwell Prince; Art by Martín Morazzo / Chris O’Halloran

Clark Kent uses Fifth Dimension powers in Superman The Kryptonite Spectrum #3 — A rainbow light floods Clark Kent as he uses Fifth Dimension powers in Superman The Kryptonite Spectrum #3

Almost as soon as he’s exposed to it, Rainbow Kryptonite makes Superman say his name backward and shoot a rainbow beam out of his mouth. The full extent of Rainbow Kryptonite’s effects will be revealed in Superman: The Kryptonite Spectrum #4, which has been teased to feature a Fifth-Dimensional Imp version of Superman called “Kal-Elf”. As Kal-Elf, Superman may have all of Mr. Mxyzptlk’s powers, plus his natural Kryptonian abilities.

DC’s Fifth-Dimensional version of Superman will likely gain the same cosmic awareness as Mr. Mxyzptlk and Bat-Mite, as well as their wicked sense of humor. Mxy can bend and reshape space, time, and logic with a thought, though he always uses his godlike abilities for mischief instead of destruction. Luckily, Superman is pure of heart, meaning the world might still be safe.

Combined with newfound Fifth-Dimensional powers, Superman’s Kryptonian physiology might make Kal-Elf one of the most powerful beings in DC history. In theory, Kal-Elf could compress suns into pebbles for fun or rewrite reality to conform to his idealistic philosophy, resulting in unexpected chaos. All of Batman’s Kryptonite tests have gotten out of hand so far, and Rainbow K may be no different.

Rainbow K’s introduction is one of the biggest changes to Superman’s Kryptonite lore since the debut of Platinum Kryptonite in 2018. Introduced in Batman Secret Files #1, Platinum K bestows Superman’s abilities on ordinary humans, essentially creating new Supermen with no apparent drawbacks. Rainbow Kryptonite works almost exactly the same, but granting Fifth-Dimensional Imp abilities instead of Kryptonian.

The Fifth Dimension Is An Overlooked Source Of Power In The DC Universe

Rainbow Kryptonite Could Be A Last-Resort Weapon For Superman And The Justice League

Mister Mxyzptlk and Bat-Mite eat popcorn while watching Superman and Batman fight

Rainbow Kryptonite could bridge the Fifth Dimension directly to Superman’s arsenal. A single shard of Rainbow K can grant Kal El Fifth-Dimensional powers, making it an invaluable edge against god-tier threats like Darkseid or Doomsday. But such power comes at a cost. Superman’s Kal-Elf transformation may be extremely difficult to contain, let alone convince to collaborate.

Batman tells Alfred that rather than a rare piece of Krypton, Rainbow Kryptonite is a distress signal from the Fifth Dimension. This makes Rainbow K even more limited than any type of actual Kryptonite. The only way to keep studying it might be through Bat-Mite, whose obsession with Batman could help Bruce Wayne gain access to DC’s most surreal weapon yet.