Cascade

Cascade is a location that appears in the anime series Sonic X. It is a planet that exist within Sonic's home universe. It is home to a different group of humans, who appears to be several times more technologically advanced than even those on Sonic's planet, who are in turn more technologically advanced than the humans on Earth.

Past
Cascade was once a beautiful planet. However, one day, the Metarex came and took the Planet Egg, causing the planet to die. A Resistance fought Pale Bay Leaf, in hope to make Cascade beautiful again. Two of the Cascade Resistance were Molly and Leon.

Metarex Saga
Later, Dr. Eggman arrived during a fight and Shadow saved Molly, causing her to believe he was the spirit of Black Wind. However, her hope vanished when Leon and several of the Resistance gave up. Molly was killed by Bay Leaf (in the Japanese version; in the English version, she is said to have left Cascade and seemingly disappeared) and Shadow, using the power of the White Chaos Emerald, got revenge by smashing Bay Leaf's ship.

After the Metarex's destruction, the Planet Egg returned to the planet making it beautiful once again. Shadow built a grave to Molly using debris and gave Rouge the Chaos Emerald, leaving to fight the Metarex alone. In the Japanese version of episode 78, Shadow was seen coming back and placing a rose on Molly's grave.

Transformers: Universe
In Transformers: Universe, Cascade is a planet. According to Misha, Cascade is a future Earth.

Cascade was a beautiful planet resembles to Earth. 30 years ago, an asteroid of Red Energon landed on the planet. In 2016, the Berger, Inc. company spaceship containing a man-made Transformers crash-landed in a lake at jungle. In 2017, the Gothamites came for the war due to the planet's civilization was more technologically advanced than the civilization on Gotham. A Resistance fought the Death Force. Two of the Cascade Resistance were Molly and Leon.

Later, Optimus Prime and the Autobots aboard the Miranda II arrived during a fight and Rodimus saved Molly from being killed by one of the Vehicons. The Autobots awakened Overhaul, the Autobot loner, harvested Red Energon by cutting many of it into cubes, captured some of the Decepticons and discovered four energon points on Cascade. Four Cybertron Cities on Cascade were established in each area one by one.

The Autobots allied with Molly, Leon and several of the Resistance and Team Bulkhead to aid in the installation of four energon towers, providing a lasting defense for Cascade against any Decepticon, Terrorcon or Gothamite attack. The Earth Federation formed a alliance with the Cascade Resistance.

Trivia

 * In the Japanese version of Sonic X, Cascade had no name.