The Cranassian is the name given to an alien race and the main antagonists of the main Raiden series that overrun Earth, but are constantly having their units destroyed by the mechanical Earth guardians, the Raiden mk-II, and the Raiden mk-II ß.
Not much is known about the menacing Cranassian race, or where they live. According to The Raiden Project, the Cranssians' homeworld was Cranass, hence their name. The only well-known feature about the Cranassians are that they use Red Crystals to generate their heavy weapons, such as the infamous Payak Colossus Tekniikan, but is seemingly no match for the World Alliance Military's most powerful weapon, the Raiden mk-II, and Raiden mk-II ß. Because of the destruction of one of the Cranassian starships, Earth is now merging it's technology with that of the Cranassian, which means, Earth now has it's own military units with Cranassian weaponry. Should ever the Cranssians begins their next invasion once more, Earth will be ready...
The Cranassians have made their appearances in all the main Raiden titles. They would seemingly rely on the Red Crystals as their source of military units, but despite the advanced weaponry the Cranassians build, the Raiden mk-II and Raiden mk-II ß were built by the World Alliance Military from one of their crashed ships, which combined Earth's most powerful technology with the machinery of the Cranassians, which resulted in a powerful weapon the Cranassians wouldn't stand a chance against.
The following below is snapshots of the Raidens battling the Cranassian mechs.