Captain Phasma is a high ranking member of the First Order. She wears a special chrome Stormtrooper armor that allows her to shield herself from heavy blaster fire as well as camouflage her with the press of a button. She is a supporting antagonist in Star Wars: The Force Awakens and in Star Wars: The Last Jedi, and the main antagonist of the first season of Star Wars: Resistance.
Star Wars Episode VII: The Force Awakens
She at first appears commanding inside the village alongside Kylo Ren, as she asked him what to do with the village. After Kylo Ren suggested to destroy it, she agreed, and she gave her command to destroy the village. When Finn took off his Stormtrooper mask, she told him to submit his blasters at once and report to her division about his act of treason, as a punishment. She later told Hux that Finn had never betrayed the First Order before. Phasma later stood next to Hux during his speech.
She was later caught by Finn, Han Solo, and their crew, and was forced to join their team and betray The First Order by tracking the Starkiller Base's shields and deactivating them. She then told them it is a big mistake to rise against Hux's command on the planet super-weapon, but she was thrown into one of Starkiller Base's trash compactors.
Star Wars Episode VIII: The Last Jedi
Captain Phasma somehow escapes The Starkiller Base and she somehow enters Snoke's mothership. She is ordered by Hux to find Finn, Rose and BB8, who enter the mothership in attempt to stop Hux from destroying the entire Resistance. Phasma finds Finn, Rose and BB8, and she arrests the three and takes them to Hux, who angrily slaps Finn on the cheek. Hux orders Phasma to torture Finn and Rose, and leaves. Phasma orders her stormtroopers to execute them, as blasters would be to good for them. However, before the execution was complete, Holdo sliced the mothership into half, as the ship started to explode and the room in which Phasma and the latter were located was collapsing. Finn, Rose and BB8 tried to escape the ship, but Phasma came out of the fire with Stormtroopers, as she was ready to kill the trio. BB8 however hacked into the First Order's fighting mechanisms as he programmed them to shoot Phasma and the Stormtroopers. Phasma was left alone, with Finn, Rose and BB8. Phasma and Finn battled, and Finn hit Phasma hard on the face, causing her to fall into a pit. Phasma struggled and told Finn that he was always a scum. Finn answered that he is a rebel scum. The pit's surface then opened, and underneath was fire. Phasma fell into the fire and most likely died.