Nebula (MCU/Guardians of the Galaxy)

Portrayed by Karen Gillan; Nebula is a Luphomoid who was adopted by Thanos after he had wiped out her civilization and turned into an assassin. to compete amongst her siblings, Nebula grew cold as she battled for dominance but always lost to the sibling she was closest to, Gamora. With every loss, Thanos replaced parts of her body with cybernetics to "improve her performance," but in reality it was a form of as punishment. Nebula grew an intense desire to kill Thanos, not being as radicalized as her other siblings, as well as besting Gamora in a fight. Nebula would work with Ronan to betray Thano, though when the executioner's plans were stopped by the recently formed Guardians of the Galaxy, Nebula went on the run. The cybernetic Luphomoid would then be captured by The Sovereign and be reunited with the Guardians just a few months later. Over time, Nebula's cold personality became warmer, eventually allying with and then joining the Guardians, acting as a co-leader.