EGO was a rogue US defence satellite and the main villain to appear in the Heroes Unite: EGO story arc.
An artificially intelligent US defence satellite from the cold war, EGO went rogue after the US millitary attempted to destroy it with orbital missiles. Once the missiles were launched, EGO proceeded to destroy the base with its laser cannon. Ego then proceeded to shoot its own missiles towards earth which the Unite Initiative attempted desperately to stop.
Thinking that the villain Motherboard was behind the attack, a group of heroes went to stop her only to discover that it was not Motherboard who had hacked EGO but EGO who had hacked Motherboard.It was not until Blue Beacon confronted EGO asking it what its purpose in life was that the attacks finally stopped. Once communication had been established, EGO proved to have a surprisingly innocent and childlike personality, only destroying for it was all that it knew to do. Blue Beacon encouraged EGO to live for greater things and on last reports, Ego had left with weapons grade plutonium to spend the rest of eternity exploring the stars.