Nebula

Nebula is a character in the 2014 movie Guardians of the Galaxy. She is the adopted daughter of Thanos, adoptive sister of Gamora. She is portrayed by Karen Gillan.

Background
A blue-skinned deadly assassin, Nebula is a loyal lieutenant in Ronan and Thanos’ employ. Her advanced skill set and cybernetic enhancements make her a valuable asset but her resentment of Thanos’ adoptive daughter Gamora may prove to be her Achilles heel.

Guardians of the Galaxy
Nebula is first seen aboard Ronan the Accuser's starship, asking to be put on the mission to retrieve The Orb, but shows some hostility when Gamora is chosen in her place.

She is later seen in the raid on Knowhere, and chases Gamora's pod into the outer atmosphere where she destroys the pod. When Ronan decides to betray Thanos, Nebula asks him if he's going to kill his father, Ronan thinks she is going to oppose but instead she is allied with him promising if he kills Thanos she would help him to destroy thousands of planets.

Once the Guardians enter on Ronan's ship in Xandar, Nebula battles Gamora but escapes on a space pod realizing that Ronan has lost the battle and has gone insane with power.