Nebula

"You're a disappointment, sister. Of all our siblings, I hated you least."

- Nebula

Nebula was an assassin in Thanos' employ and enemy of Guardians of the Galaxy.

Guardians of the Galaxy Prelude
Raised in the service of the interplanetary warlord Thanos as his adopted daughter, Nebula trained to be a Galaxy-Class Killer. Nebula would often train along Thanos' other adopted daughter Gamora. One training scenario on the arboreal world of Dervani saw Nebula and Gamora pitched against each other in a competition to retrieve a data ingot for Ronan. The girls sparred on the surface, leading to Gamora throwing Nebula of a cliff, severely injuring her and requiring multiple cybernetic replacements. Upon reaching adulthood, Nebula was sent on a mission to locate The Orb for Thanos, on the planet Praxius IX, inside of one of the Cloud Tombs of Praxis, Nebula fell into a trap. Ensnared by an impenetrable Laser Thorn Energy Net, Nebula found herself at the mercy of the inhabitants and needed to be rescued by Gamora. Never one to tolerate failure, Thanos ordered Gamora to leave Nebula behind, with only a sharp blade to free herself. Nebula was forced to amputate her own arm in order to escape the netting.

Guardians of the Galaxy
A blue-skinned deadly assassin, Nebula is a loyal assassin in Thanos’ employ. Her advanced skill set and cybernetic enhancements make her a valuable asset but her resentment of Thanos’ other adoptive daughter Gamora may prove to be her Achilles heel. Thanos lends her services to Ronan the Accuser to help him retrieve The Orb. When Korath returned to Ronan's ship, the Dark Aster, to report that the Orb is in the possession of a thief named Star-Lord and that he planned on selling the Orb on Xandar, Ronan volunteered Nebula to retrieve it. However, Gamora strongly insisted that she recover the Orb, stating that she knows Xandar better than Nebula. Though Nebula protested, Ronan agreed to send Gamora in her place.

Nebula and Ronan are then summoned to Sanctuary, where Ronan lays out his grievances to Thanos, ending with killing the Other. Thanos then threaten to "bathe the stars in Ronan's blood" if he failed to recover the Orb, at which Nebula stated that it would be a pleasure to carry out.

Ronan and Nebula arrive at the Kyln, only to learn that Gamora and some others had already escaped with the Orb. As a Nova Corps fleet was arriving to defend the prison, Ronan ordered the prison massacred to hide their objectives. Ronan was eventually contacted by Drax the Destroyer that the Orb was on Knowhere. Nebula then pursued Gamora in an aerial battle. Before destroying her sister's craft, she remarked that of all her siblings, she hated her the least. Though the blast didn't incinerate Gamora, it left her and the Orb floating in space, the latter of which Nebula retrieved.

Returning to the Dark Aster, where they got in contact with Thanos, Ronan discovered that the Orb contained an Infinity Stone and decided to betray the Mad Titan, planning on destroying Xandar himself and then kill Thanos. Nebula chose to side with him, stating that if he succeeds in killing her father, she will help him burn a thousand worlds.

As the Dark Aster descended on Xandar, Nebula informed Ronan that a fleet of Ravagers were en route to intercept them. Nebula then ordered all fighters squadrons to deploy and attack. But even as the Nova Corps joined the battle, Ronan dismissed them as threat, stating that none of it would matter once he's won. Nebula then went to confront Star-Lord, Gamora, Drax and Groot. As she laid her disappointment in Gamora, she is interrupted by Drax, who blasts her with a cannon. Recovering, Nebula engaged Gamora in melee combat, but is ultimately overpowered by her sister and left hanging at the edge of a hull breach. Gamora offered to save her, stating that Ronan is insane. Labeling Gamora likewise, Nebula severs her left wrist and falls onto a passing Ravager ship which she commandeers and flees the planet.

Guardians of the Galaxy Vol. 2
To be added

Avengers: Infinity War
To be added

Character traits
Nebula is an adopted daughter of Thanos, who augmented her and converted her into a cyborg. Despite her familial ties to Thanos, she allies herself with Ronan the Accuser when she aquires an Infinity Stone for him to destroy Xandar and later wanted to use it's power against Thanos.

Relationships

 * Peter Quill - Enemy.
 * Drax the Destroyer - Enemy.
 * Groot - Enemy.
 * Rocket Raccoon - Enemy.
 * Nova Corps - Enemies.
 * Gamora - Adoptive sister and ally turned enemy.
 * Thanos - Adoptive father and ally turned enemy.
 * Ronan - Ally.
 * Korath - Ally.
 * The Other - Ally.

Appearances/Actresses

 * Marvel Cinematic Universe (3 film)
 * Guardians of the Galaxy (First appearance) - Karen Gillan
 * Guardians of the Galaxy Vol. 2 - Karen Gillan
 * Avengers: Infinity War - Karen Gillan
 * Avengers 4 - Karen Gillan
 * Guardians of the Galaxy Vol. 3 - Karen Gillan
 * Marvel Cinematic Universe (1 comic)
 * Guardians of the Galaxy Prelude

Behind the scenes

 * Karen Gillan shaved her head for the role in the first film and wore an skullcap in the second film.
 * Karen Gillan was once believed to play Angela.

Trivia

 * In the comics, Nebula is a space pirate and mercenary rather than an assassin and Thanos is her alleged grandfather rather than adopted father.
 * In the comics, Nebula is a recurring foe of the Avengers and the Silver Surfer rather than the Guardians of the Galaxy.