Ridley (Metroid)
Often considered one of the most memorable Nintendo villains, Ridley has been a mainstay of the series, having appeared (through various incarnations) in almost every "Metroid" game to date (all but "", "Metroid Prime Hunters" and ""). He has also appeared in the "Super Smash Bros." series, however, he had not been made a playable character until "Super Smash Bros. Ultimate" in 2018, making it also the first game overall to have Ridley as a playable character.
Characters in the Metroid series
However, this project was foiled by the accidental cloning of Ridley and the rebellion of MB, the Mother Brain-like android created to control the Metroids. This leads to the interference of Adam Malkovich's team of soldiers and Samus. However, one of their operatives called ""The Deleter"" by Samus, infiltrates Adam's squad to remove any evidence of the project. While it is not explicitly stated, the Deleter was in fact James Pierce, the squad's communications expert. The presence of Samus derails James' mission, though he does manage to kill several members of Adam's squad before he himself was found dead in the Bioweapons Research Center: it can be surmised that he tried to eliminate MB, but failed. An unnamed scientist who cleans the Metroid and Ridley's DNA off Samus is implied to be a member or operative for the group. Additionally an unnamed GF colonel who orders MB's destruction and attempts to force Samus to handover Madeline Bergman using the fact she is an outsider to force her to comply is implied to either work for or a top ranking member of the group and may have been the one responsible for sending the Deleter to eliminate Adam and his team before they could uncover and expose their bio-weapons research as he is a member of the Galactic Federation military. The actions of Samus and Adam's heroic sacrifice put an end to their bio-weapons research on the Bottle Ship, but their secret bio-weapons research and Metroid breeding program continues on the B.S.L. research station until it is overrun by the X parasites. In "Fusion", Samus discovers the continued bio-weapons research and learns that they foolishly plan to capture the X parasites and the SA-X for the bio-weapons research, and crashes the station into the planet SR388 with the help of her ship's AI, which was based on Adam Malkovich.