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
The heavy trauma of having Madeline rejecting her safety and finding out that the Galactic Federation actually created her for military purposes caused a meltdown in her mind and she decided to take judgement on humanity for their misdeeds, forcing the Bottle Ship in a collision course. Melissa was confronted by both Samus and Madeline after her Queen Metroid had been killed. Although both of them tried to persuade her, she did not listen and tried to kill Madeline, only to get shot down by the Marines under the Federation colonel's orders.