Chaos Emeralds

Chaos Emeralds (カオスエメラルド) are a set of seven emeralds containing a high level of power that originated from Sonic the Hedgehog's dimension. They came in Blue, Cyan, Green, Yellow, Red, Purple, and Silver.

Story
After the events of the first Genesis Wave, the Blue Chaos Emerald somehow ended up transported to the Amazon in Earth 20XX, Mega Man's realm. Flash Man, a Robot Master on patrol in the area, uncovered it. He then brought it back to his master, Dr. Wily, and reported his findings while the latter argued with Ra Moon about his desire to create a Met with a rice cooker function. Wily initially thought it was a sapphire, although Flash Man replied that a spectral analysis on the gem indicated it was a beryl, with Wily commenting that it may be an aquamarine and that he isn't a geologist anyway. Wily tried to have it analyzed due to Ra Moon commenting that it had some sort of great power. He initially thought it was a new Energy Element, although the power output caused the scanner to blind Wily and Flash Man. The Chaos Emerald allowed Wily to get into Dr. Eggman's transmission, who had been tracking down its location since its disappearance, and then the two doctors formed an alliance, using the Chaos Emerald to create the Skull Egg Zone.

Upon creating the Wily Egg and using a Genesis Wave to rewrite reality not only on Mobius, but also in Mega Man's dimension, the two doctors proceeded to locate the remaining Chaos Emeralds, which scattered between the two dimensions after the alterations. The Roboticized Masters Knuckles Man, Rose Woman, Shadow Man, and Tails Man, alongside Metal Sonic, were later dispatched to Mega Man's dimension to rob the Chaos Emerald in Mega City's first national bank. They met some resistance against Mega Man and Proto Man, although they ultimately escaped due to Metal Sonic's interference. The Roboticized Masters, save for Tails Man, later returned to the Skull Egg Zone to report the success of their retrieval of the Chaos Emerald while Wily and Eggman watched Sonic the Hedgehog and Mega Man fight each other. Later, Silver Man and Blaze Woman returned with the Green Chaos Emerald. When the doctors admitted they already had all seven Chaos Emeralds, Tails reacted with horror, although Mega Man was unfamiliar with them, causing Sonic to explain that they were equivalent to Mega Man's realm's most powerful energy source (Energy Elements) times a billion. They then used it to power the Genesis Wave Generator in order to become demigods of time and space. Later, Sonic and Mega Man (the latter via the Rush Super Adaptor) then entered into super forms and managed to stop Wily and Eggman, with Mega Man's dimension returning to normal.