Xevious are fictional alien villains from the Xevious franchise, and they serve as the titular main antagonists of the franchise. According to the universe of Xevious franchise, Xevis are the original inhabitants of the planet Earth.
Xevious tells the story of the fight between humankind and the biocomputer GAMP, which controls the alien forces of planet Xevious.
GAMP or G.A.M.P. (General Artificial Matrix Producer for short), is the name of the supercomputer that controls all the alien forces on the planet Xevious. It serves as the main antagonist of the Xevious series.
100,000 years ago, GAMP was created by an ancient civilization on earth with the purpose of generating human clones to serve their creators. Over time, however, GAMP made clones that began to believe that humanity was inferior and that they have to "protect" it by rebelling against their creators, which worked because the clones were stronger than their creators.
Then came the Ice Age and to escape the upcoming Ice Age, GAMP and the human clones migrated from Earth in search for a new home. They chose six planets (including planet Xevious) that were suitable to human life. Before leaving Earth, GAMP manages to plant artifacts and relics. 4000 years later, a human named Mu and his robot female friend, Eve, decided to leave Earth and go to Xevious. What the two received upon their arrival was anything but hospitality: they got captured, imprisoned, and later made a rebellion against GAMP. While Mu and Eve were in their imprisonment, they discovered that the Xevians were planning a massive homecoming on the Earth.
While Mu and Eve escaped and are still on Planet Xevious, on present day the Xevious Armada led by GAMP decided to invade Earth: near the ancient civilization remains, giant artifacts that GAMP planted thousands of years ago suddenly emerge from the soil and activate: they are SOL towers, buried underground and inactive for eons, now responding to GAMP's orders.
Thus began the war between Mankind and Xevious Armada.
The war was fast: Using advanced technologies, vast military forces combined with their most powerful arsenal named Bacura which is indestructible to any known weaponry, GAMP's Xevious Armada quickly overran Earth's military alliance and took over Amazon Jungle in South America. It is then Solvalou spacecraft piloted by Mu and Eve, came across the space to save Earth from GAMP's tyrannical domination. Meanwhile on Earth, archaeologists Susan Meyer and Akira Sayaka discovered that the Nazca lines could be hiding an ancient weapon that may be used to counterattack Xevious Armada.
In Xevious: Fardraut Densetsu, GAMP clones itself. Unfortunately for GAMP, his plans are foiled when Solvalou defeats GAMP, which fatally injures the 6 Replicas because GAMP was linked to the replicas. However, a replica of GAMP appeared in Xevious 3D/G and another one appeared in Super Xevious: GAMP no NAzo, implying that GAMP had some back-up replicas.