Nebula

"After Xandar, you're going to kill my father?" "You dare to oppose me?" "You see what he has turned me into? You kill him and I will help you destroy a thousand planets."

- Nebula and Ronan the Accuser

Nebula is a Luphomoid assassin and an adopted daughter of the intergalactic warlord, Thanos. She is also the adopted sister of Gamora. She served as the right-hand woman of Ronan the Accuser during his and Thanos' quest to retrieve the Orb.

Trained for Thanos
"As a child my father would have Gamora and me battle one another in training. Every time my sister prevailed, my father would replace a piece of me with machinery. Claiming he wanted me to be her equal but she won again and again and again, never once refraining."

- Nebula

Raised in the service of the interplanetary warlord, Thanos, Nebula trained to be a Galaxy-Class Killer under the tutelage of Ronan the Accuser. Nebula would often train alongside other fellow Thanos devotees Gamora and Korath.

Thanos regularly had Nebula spar with Gamora to test their strengths with Gamora winning every match. Every time Nebula lost, Thanos would 'upgrade' her to try and make her Gamora's equal. Nebula grew to resent Gamora for never letting her win causing Thanos to torture her.

During 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 off a cliff, severely injuring her and requiring multiple cybernetic replacements in order for her to live.

Upon reaching adulthood, Nebula and Gamora served Thanos under the command of Korath the Pursuer. On a mission to locate the Orb on the planet Praxius IX, inside of one of the Cloud Tombs of Praxius, Nebula went in without waiting for Gamora and 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.

Following Ronan's Orders
"You think I don't know? You would keep me from advancing! You would have Ronan tell father only Gamora furthers his great plan!" "I will keep you alive!" "Compassion? What would Ronan say to that?"

- Nebula and Gamora

Thanos lent Nebula and Gamora to the Kree warmonger Ronan the Accuser, who made a deal to retrieve the Orb for Thanos so he would in turn destroy Xandar. When Korath the Pursuer reported that he had failed to retrieve the Orb on Morag, thanks to Star-Lord's intervention, Nebula was tasked to retrieve the Orb from Star-Lord. Nebula told him it would be an honour but Gamora insisted that she follow Quill as she knew Xandar. Ronan agreed and Gamora went on the mission. When they left the meeting, Nebula confronted Gamora and they had a brief argument where they tried to break each other's fingers. Nebula accused her sister of now attempting to become Ronan's favourite and they discussed who was the supiour killer. When Nebula mentioned that the screams of her victims could be heard across the galaxy, Gamora replied that it was because she took too long to kill them before walking away from Nebula. When Ronan and Nebula recieved word that Gamora had betrayed them only to be sent to the Kyln with the Orb, The Other demanded they travel to the Sanctuary to discuss this with Thanos. There, Nebula repaired her cybernetic arm while Ronan argued with The Other, only for Ronan to snap his neck. Thanos responded by threatening Ronan if he failed again. As they left, Nebula assured Ronan that he would not win a fight with her father. When they arrived at the Kyln, they discovered Gamora had already escaped with the Orb, with the help of Star-Lord and others. Ronan's soldiers took over the prison and Nebula tortured a Nova Guard to gather more information. She received a message on her cybernetics that the Nova Corps were on their way to defend the prison. As they were leaving Ronan ordered Nebula to send their Necrocraft across the galaxy to begin the search for Gamora and to cleanse the prison, murdering all of the guards and the prisoners.

Skirmish on Knowhere
"You are a disappointment sister; out of all our siblings, I hated you least." "Nebula, please. If Ronan gets this stone he’ll kill us all." "Not all. You will already be dead."

- Nebula and Gamora

Following the orders of Ronan the Accuser, Nebula and Korath the Pursuer continued their search for the Orb across the galaxy onboard the Dark Aster, until they received a message from Drax the Destroyer telling them it was on Knowhere where they went to recover it. Upon arriving onboard Necrocraft and their army of Sakaarans, they were spotted by Gamora and her new team, who escaped into a Mining Pod while Nebula gave chase with her small army.

While Ronan began fighting with Drax, whose wife and daughter had been killed by the Kree, Nebula lead a squad of soldiers in fighters to chase Gamora across Knowhere, while fighting off Star-Lord and Rocket Raccoon who defended their ally. Eventually Gamora was forced to head into deep space which shut down her pod. Nebula destroyed her ship, despite her pleas, and leaving her for dead in space and retrieved the Orb for her master Ronan. Both Nebula and Korath the Pursuer were present when Ronan the Accuser told Thanos he was aware of the Orb's nature as one of the Infinity Stones. Ronan ripped open the Orb and harnessed its power, becoming the most powerful being in the universe. Ronan told Thanos he would destroy Xandar and then find and destroy The Mad Titan. Nebula offered her total loyalty to Ronan should he succeed, swearing to help him destroy a thousand planets.

Battle of Xandar
"The starboard kern has been breached! We have been boarded!" "Continue our approach." "But the Nova Corps have engaged!" "None of that will matter once we reach the surface."

- Nebula and Ronan the Accuser

When they arrived on Xandar, a fleet of Ravagers lead by Yondu Udonta and Star-Lord engaged them. The fleet fired a blot of flame to disguise their moves, but Nebula saw that they had dived under the ship and she ordered all their fighters to destroy the ships. Once they received word that the side of the ship had been breached, Nebula tried to convince Ronan the Accuser to retaliate but he refused, stating that his focus was to land on the planet's surface so he could finally destroy it. Deciding to take matters into her own hands, Nebula took a squad of soldiers with her to engage the attackers before shutting the door, locking in Ronan. When Star-Lord, Gamora, Rocket Raccoon and Drax breached the ship, Nebula confronted them. As Nebula began to insult her former sister she was silenced when Drax shot her with a rocket, sending her flying backwards and damaging her body while allowing the Guardians to continue on their mission.

Duel against Gamora
"Sister! Help us fight Ronan! You know he is crazy!" "I know you're both crazy!"

- Gamora and Nebula

The shot fired by Drax the Destroyer caused Nebula's entire body to be damaged, but her cybernetic implants helped to repair her within moments, twisting her arm and jaw back into place. Once she was repaired Nebula began to fight Gamora, using her electrified batons against Gamora's Godslayer. During their fight against each other, the side of the ship was suddenly torn apart by an explosion as the Battle of Xandar between the Ravagers and the Sakaarans continued on. During their fight, Gamora attempted to unlock an armoured door to assist the Guardians of the Galaxy, however Nebula did all she could to delay this action. Eventually Nebula managed to gain the upper hand and began disarmed Gamora before she used her batons to electrocute Gamora, nearly killing her. However Gamora regained her strength and knocked her outside of the hole in the Dark Aster and leaving Nebula hanging onto the edge of the hole. As Nebula hung hundreds of feet above Xandar's surface, with her hand trapped onto a spike, Gamora tried to convince her to fight against Ronan the Accuser, claiming Ronan was crazy. But Nebula refused, citing they were both crazy and cut off her cybernetic hand. However, instead of falling from the sky to her death, she landed on top of a Ravager's M-ship. Nebula then threw the pilot out and took control of the ship before flying it far away from the battle.

Arrest
Some time later, Nebula was arrested by Ayesha and the Sovereign for trying to steal expensive interdimensional batteries. Six months after the Battle of Xandar, the Guardians of the Galaxy took custody of her to hand over to the Nova Corps. As the Milano piloted away, Nebula was handcuffed inside the ship and demanded food being ignored by the Guardians.

When the Sovereign fleet attacked after Rocket stole the batteries, Nebula was almost sucked out of the ship but escaped her restraints. Her hands remained handcuffed and she demanded to be released after they crashed on Berhert to fight whoever was in the unidentified craft.

Escape
Nebula witnessed Ego's revelation that he was Quill's father. The next day she was left in the Milano with Rocket and Groot whilst Gamora, Drax and Quill went with Ego and Mantis.

When Yondu and the Ravagers attacked the Milano, she managed to persuade Groot to release her before shooting Yondu's fin and then shooting Rocket in the chest. She was taken aboard Yondu's ship witnessing the mutiny led by Taserface before demanding 10% of the bounty Ayesha had placed on the Guardians as well as 'some other things'.

Nebula was given a new cybernetic arm by Kraglin as well as an M-Wing. She informed him of her upbringing with Thanos and how he had 'upgraded' her every time she lost a sparring match to Gamora. Nebula explained that after she killed Gamora she would use her 10% to buy every ship she could to kill Thanos.

Fight with Gamora
Nebula flew to Ego's Planet and began firing at Gamora pursuing her into caverns before being trapped as her M-Wing prepared to explode. She was rescued by her sister but instead of being grateful attacked her sister but couldn't kill her. The pair formed an uneasy alliance after Nebula revealed her anger at Gamora's attitude during their upbringing.

The two sisters walked through the caverns and discovered a large pile of bones.

Battle of Ego's Planet
Nebula and Gamora rushed back to the palace and confronted Mantis who agreed to help them. Along with a Drax, they burst into the main hall to find Ego attacking Quill before a ship piloted by Yondu and Rocket crushed him. Nebula agreed to help as the Guardians were her only ride off of Ego.

During the battle, she wired the ship up to her cybernetic arm to provide power to the lasers which electrocured her and caused her great pain but destroyed the Sovereign fleet. When the ship was destroyed she joined the Guardians in the heart of the planet to continue to fight. When Ego attacked, Nebula saved Gamora from falling to her death with the sisters climping back up to the fight before being trapped and suffocated in organic matter. When Quill took control, they were both released and reached the ship piloted by Kraglin.

Aftermath
Nebula prepared to leave during Yondu's funeral. Despite Gamora's attempts to persuade her to join them, she chose to leave and try to kill Thanos instead and prevent others daughters of knowing the same fate that hers. The two sisters hugged before Nebula departed.

Personality
"I am every inch the warrior you are. The screams of my victims fill every field."

- Nebula to Gamora

Like Gamora, Nebula despises her father, Thanos, for torturing her and turning her into a cybernetic assassin. However, despite this, she always tried, often in vain, to prove her worth to her father. Nebula resents Gamora for being Thanos' favorite daughter, which he has openly expressed even with Nebula present and she showed no hesitation in trying to kill Gamora more than once. Despite this Gamora doesn't not share these feelings for Nebula and even tried to convince her to betray Ronan the Accuser and help the Guardians of the Galaxy fight him even after trying to kill her twice.

Nebula has very little loyalty to a cause as she quickly betrayed Thanos once Ronan harnessed the power of the Orb, believing he could kill Thanos as he declared to do so. However when the Battle of Xandar became too intense for her liking she quickly abandoned Ronan to escape, despite her sister's pleas for her to help the Guardians, possibly returning once again to Thanos. Unlike her sister who seeks to atone for her past crimes Nebula does not show any visible signs of regret for her own crimes as she was perfectly willing to murder anyone tasked to her and anyone who stood in her own way.

Ironically, despite her claims of hating her sister and her actions against her, it seems she does care for Gamora greatly. When Nebula destroyed the ship Gamora was in outside Knowhere, Nebula genuinely believed that she was doing Gamora a favor as she doubted that Thanos or Ronan would be so merciful as to give her a quick death as punishment for betraying them and stealing the Orb for herself.

Powers

 * Luphomoid Physiology
 * Superhuman Strength: Nebula has strength greater than that of a human being. She managed to throw a pilot of an M-ship out of the vehicle in mid-air with ease.
 * Superhuman Durability: Nebula can easily withstand multiple injuries. She managed to jump onto a M-ship from an great height without withstanding injuries.
 * Superhuman Agility: Nebula has agility greater than that of a human being. She can easily keep up with Gamora in a fight.
 * Cybernetic Enhancements
 * Nebula-Broken-Jaw.pngRegenerative Healing Factor: Nebula's cybernetic implants allow her to quickly heal from otherwise near-fatal injuries, such as when her body was crushed and mangled when withstanding a direct blow from Drax's cannon. Thanks to her implants, she was able to reshape her body back to its original form by snapping her arms and jaw back into their normal place.

Abilities

 * Master Assassin: Ever since she was a child, Nebula has trained extensively as an assassin under Thanos and Ronan. She trained with Gamora throughout her childhood.
 * Expert Combatant: An expert in armed and unarmed combat, Nebula was able to fight "the deadliest woman in the galaxy," Gamora, for a prolonged amount of time. She has been seen using retractable, baton-like electroshock weapons in battle which can be combined to form a longer electroshock staff.
 * Expert Pilot: Nebula is an expert pilot, easily flying over a mining pod and an M-ship.

Cybernetic Enhancements
In her early years under Thanos' wing, Nebula received various critical injuries that required her to endure extensive cybernetic augmentation.
 * Contact Whiplash
 * Tempersteel Claws
 * Concussive Blasts

Weapons

 * Electroshock Weapons: Nebula's weapon(s) of choice are baton-like electroshock weapons which can be combined to form a longer electroshock staff.

Allies

 * Ronan the Accuser † - Master
 * Korath the Pursuer †
 * The Other †
 * Guardians of the Galaxy - Former Enemies turned Allies and Former Teammates
 * Peter Quill/Star-Lord
 * Gamora - Adoptive Sister and Former Rival
 * Drax the Destroyer
 * Groot
 * Rocket Raccoon
 * Mantis
 * Yondu Udonta †
 * Kraglin Obfonteri

Enemies

 * Thanos - Adoptive Father and Former Master
 * Nova Corps
 * Head Riot Guard † - Victim
 * Ego the Living Planet †
 * Sovereign - Former Captors
 * Ayesha

Trivia

 * Nebula's appearance in the movie seems to be based more on her second incarnation from the comics.
 * Nebula shows complete loyalty to Thanos most of the time, but also states that she would gladly destroy a thousand worlds if it meant Thanos would die. This is possibly out of fear towards him, but may also be out of hatred, due to Thanos constantly undermining her in favor of Gamora.
 * In Guardians of the Galaxy Prelude, Nebula loses her entire left arm and has it replaced by cybernetics; however, in Guardians of the Galaxy, her left hand appears to be made of flesh.

Behind the Scenes

 * revealed she was up for the role of Nebula.