The Alien Exterminating Global Intercept System, This group was formed by the United Nations in the wake of Invader's appearance at the end of World War 2.
A.E.G.I.S. collected the Gatekeepers who were the only ones able to slay an Invader. This came to a head in 1969 when the Invaders under their new leader Shadow launched an invasion of Japan, A.E.G.I.S. central command in New York under the U.N. declared the island nation lost. However A.E.G.I.S.Japan was able to defeat Shadow. Now revealed as Kageyama Reiji.
In 1970 A.E.G.I.S.was disbanded due to the efforts of Invader boss Mugen Majuu who had impersonated the Supreme Commander of A.E.G.I.S.
However, knowing that the invaders were still out there. Kageyama had the idea to form A.E.G.I.S. Network in 1985 to coordinate the efforts of the Gatekeepers in the hunt and destruction of the Invaders.
Now an Illegal organization, the A.E.G.I.S. Network works from the shadows hunting the Invaders down and destroying them.