Enter is an Avatar, created by Psycho using the data of deceased GPU scientist William Miles. (Ironically, Professor Miles was the one who originally created Psycho.) He was created for the sole purpose of gathering Enertron, an experimental energy source, in order for Psycho to be able to cross back over from Hyperspace into our realm so that he can enact his revenge.
As an Avatar, Enter has no physical form; rather, he is made of pure data and energy, and can materialize and teleport at will. His main method of attack is to use his Metavirus cards to infect inanimate objects, which will then transform into Metaloids, attack robots that he then sends to attack the Rangers and gather Enertron. In the event of a Metaloid's defeat, he can also resurrect them using his energy-tendrils, allowing them to pilot a giant robot that he teleports from Hyperspace. (Though this requires a large amount of Enertron, meaning Enter cannot always do so.) As a creation of Psycho, he harbors a deep hatred of humanity-especially the Rangers, and he will do anything it takes to destroy them.
In addition to his plans to destroy the Rangers, Enter is always working on his own projects behind the scenes, unbeknownst to his master. Just what is it that this Avatar is planning?