The Infinity Stones are powerful artifacts that exist in certain realities of the multiverse, with the power to control and influence different aspects of said realities.
Vultroverse
Originally, the stones were unknown for most of time. They were reduced to atoms after the events of the Super Genesis Wave, meaning that they were never discovered. Thanks to Solidus the Werewolf making contact with Otto Octavius, he and Dr. Eggman became aware of their existence. In the Vultroverse, they are known as the Infinity Emeralds.
Dr. Robotnik, eager to obtain the power of the stones, travels back in time and causes a war for the stones in the early 21st century.
In the Vultroverse, the emeralds are named after components of music.
- Tempo - Manipulates and controls time. Color is lime green.
- Groove - Reveals hidden knowledge about living beings. Color is sky blue.
- Timbre - Temporarily alters the appearance of objects. Color is red.
- Harmony - Influences and controls minds. Color is golden yellow.
- Melody - Draws and amplifies natural power from the surrounding environment. Color is purple.
- Metre - Manipulates and controls matter. Color is pearl white.
There was also the Rhythm Emerald. This was a fake pink-colored emerald created by the Avengers as a distraction to Dr. Robotnik. It was claimed to control the distance between points in space, a power actually possible with a combination of the other stones. The tendency for gems of power to come in groups of seven added to its credibility.
As it turns out, the Shoten Crystal is also compatible with the stones, creating a pseudo seventh stone called the Dynamics Emerald. It is capable of amplifying the power of the Infinity Emeralds to the scale of being able to influence the entire universe without so much as a scratch on the wielder.