Nya

Nya is the younger sister of Kai, and Samurai X is her alter-ego. At one point, Sensei Wu was considering training her to be a full-fledged ninja, although this changed when she assumed the role of Samurai X instead.

Way of the Ninja
While Kai and Nya are working at Four Weapons Blacksmith, Sensei Wu walks in and browses the shop, commenting that none of the items are suited for a ninja. At first Kai is hostile and tells him to leave if he's just going to loiter, but with Nya's encouragement he attempts to make a sale, only to find that the man is already gone. Moments later, a dark cloud appears over their small village. On top of a nearby hill, the Skull Truck appears along with many other skeleton vehicles. Kai prepares to fight them with some of the armor and weapons from his shop, telling Nya to wait inside. Not happy with the idea, she quickly joins Kai in the fight despite his protests. Kai attempts to face off with Samukai, but the Skulkin General disarms him with ease, forcing Sensei Wu to come in and use his Spinjitzu to distract him. Samukai throws his bone daggers at the water tower close by, sending it falling towards Kai. Before it can land, Sensei Wu pulls him out of harm's way. Samukai then commands Kruncha to take Nya, and they fall back with her in tow.

King of Shadows
Sleeping in the Forest of Tranquility, Kai wakes up to see Nya standing nearby and calling his name. She then runs off, luring him out to the Fire Temple. When he reaches the Temple, the Nya he sees reveals herself to be a shadow of Lord Garmadon. After some taunting, Lord Garmadon reveals the real Nya suspended by a chain over the lava, and tells Kai the only way to save her is to cut the chains with the Sword of Fire. Although reluctant to be playing into Lord Garmadon's hands, Kai is quick to pull the sword out of its pedestal and save Nya. Kai begins fighting several shadow versions of himself, but realizes his blows can't make contact. Sensei Wu arrives and defeats all the shadows using his own. Garmadon awakens the Fire Dragon, and Sensei Wu, thinking the only way to stop his brother is to go to the Underworld with the Sword of Fire, departs, leaving Kai and Nya to fend for themselves.

Weapons of Destiny
Cole, Jay, and Zane go to the Fire Temple to look for Kai and Sensei Wu, but Zane's sixth sense tells them they are not there. Moments after Zane informs them of the news, they hear Kai's voice, and the Temple splits in two to reveal Kai and Nya riding the Fire Dragon. After explaining to the Dragon that they were trying to protect the Golden Weapons, the Dragon seemed to agree to help them out. Nya mentions that their father used to tell them stories about the Dragons and how they ferried between their world and the Underworld. Kai and Nya agree to part ways, and Nya tells the Ninja that she'll be waiting back at the shop for their safe return. When the Ninja return to the shop, Nya is there to greet them. She hugs Kai and Jay, relieved that they are safe.

Secrets of the Blacksmith
Jay is flying Nya back to the Four Weapons Blacksmith shop on the Lightning Dragon so she can pack up and move in with the Ninja. Inside the shop, she starts packing when Wyplash, along with three of his minions, sneak up on her. After briefly distracting the group, she knocks Wyplash and Krazi to the ground before springing a trap on Chopov and kicking Bonezai. She continues to fight the Skulkin as they start to overtake her. She manages to take the upper hand by cleverly using a gong, but the noise catches Jay's attention and he comes charging in, only to find Nya alright. He questions what the commotion was about, but she explains it was just some of the items around the shop. Jay and Nya then fly back to the Monastery, and Wyplash tells his henchmen that this remains between the four of them.

Rise of the Snakes
While the Ninja are warned by Sensei Wu not to let their laziness get the best of them, Nya rushes in and informs them that Lord Garmadon has been spotted in Jamanakai Village. After the Ninja had dealt with Lloyd Garmadon instead, Nya decides to visit Jamanakai Village and sees Lloyd had already returned with the Hypnobrai. When the Ninja hear of the Serpentine threat from Sensei Wu, Kai realizes that Nya is currently there, and the four of them head out on their Dragons. After witnessing the Serpentine and the villagers they had hypnotized, they meet up with Nya. She tells them not to look the Hypnobrai in the eyes when they rattle their tails, and also mentions that the General of the tribe is holding the Hypnobrai Staff, which contains the anti-venom to cure the villagers. Jay then offers for her to be an honorary member of their team, much to her annoyance. Cole manages to take the Hypnobrai Staff from Slithraa, but just as Skales hypnotizes him, Nya comes in and kicks Skales in the face, causing him to retreat. She then tells Cole to use the staff on the fountain in town, so the anti-venom can be distributed through the water supply and restore the villagers back to their normal selves.

Can of Worms
After Pythor stole the Map of Dens from Lloyd, Nya figured out the locations of the Constrictai and Venomari tombs based on the locations of the first three tombs. Later, when the Ninja were trapped in the Toxic Bogs, Samurai X arrived and pulled them to safety before scaring off the snakes. When the Ninja approached the Samurai to thank her, she sprays them with a sleeping gas. She then flies off just as the Destiny's Bounty arrives.

The Snake King
After the Ninja get their new ZX suits, Nya reports that Serpentine are terrorizing the amusement park. The Ninja are more than ready to reply to the call. Upon arriving, however, the Ninja find that Samurai X has taken care of the snakes, tying them up in rope. The Ninja are under the belief that whoever catches the Samurai will be the Green Ninja, and so place a bet. A montage shows how they try in different ways to capture the Samurai, but to no avail. Back at the Destiny's Bounty, the Ninja complain about their failed attempts to try and capture the Samurai. After realizing Lloyd isn't with them, the Ninja track him down to The Lost City of Ouroboros. However, upon arriving they realize it's a trap when they are captured by Pythor. Pythor announces another Slither Pit for the entertainment of the Serpentine, to find out whether the Ninja or Samurai is stronger than the other. Although seeming to fight, Samurai X reveals he was just putting on a show until an opportunity presented itself, and helps the Ninja escape. After the Samurai's exo-suit malfunctioned, they landed in the desert. Cole, Zane, and Jay landed together in the desert, but Kai landed nearby the Samurai, when he discovers that Nya is Samurai X. After a discussion, Kai promises not to tell the others about her secret.

Once Bitten, Twice Shy
Jay asks Nya out on a date, to which she agrees. However, Jay is informed of Serpentine activity at the Mega Monster Amusement Park, forcing him to cancel his date with her. As an alternative, they both decide to hold their date at the amusement park instead, although their time together is ultimately ruined by the Serpentine.

Double Trouble
While the Ninja are helping Lloyd train at the dojo, Nya walks into the room and invites Jay to come by the auto body shop, mentioning how he can help her fix the Ultra Sonic Raider in her off time. Later on, she is seen working on the Ultra Sonic Raider when Jay's Doppelganger shows up. He kisses her as a distraction while he takes the keys to the vehicle and drives off, Nya not realizing it wasn't the real Jay.

Wrong Place, Wrong Time
While the Ninja were training the newly-aged Lloyd, Nya entered the training room with a watermelon, only for Zane's shurikens to be embedded in the fruit after Lloyd dodged the attack. Nya commented on how quickly Lloyd was improving, but Sensei Wu told his students to try the exercise again without holding back.

Later, Nya joined the others in infiltrating the Lost City of Ouroboros for what they assumed would be their final battle against Lord Garmadon. When Lloyd froze the tip of Garmadon's Mega Weapon, the villain fled and left his minions to fight the Ninja; after defeating the Serpentine, Nya broke down the door of the building Garmadon had fled to, only to find an open time portal that Garmadon had summoned. As they contemplated the new twist, Ouroboros began to flood with sand - Zane identified this as a consequence of the past being altered. While the Ninja leapt through the portal to undo whatever damage Lord Garmadon was doing, Nya joined Sensei Wu and Lloyd in fleeing the city before they were buried alive.

In the past, the Ninja discovered Lord Garmadon's plan was to ruin the Skulkin's attempt to kidnap Nya (as seen in "Way of the Ninja"), thereby removing Kai's motivation to train. Despite this, the Sensei Wu of the past was still able to convince Past Kai to come to the Monastery, largely due to Nya encouraging him to go. Unfortunately, Past Kai was highly unmotivated since his sister was with him, forcing the Ninja of the present to kidnap Past Nya and deliver her to the Skulkin. During the kidnapping, Jay almost blew his cover when he automatically apologized to Past Nya for capturing her, but Past Nya was in too much of a fury to care.

After being delivered to the Skulkin, events transpired in the same way as before for Nya until her brother rescued her at the Fire Temple. Instead of his own shadows, Past Kai was attacked by the future version of Lord Garmadon, who had formed an alliance with his past self. More bizarrely still, Nya then bore witness to her brother fighting alongside the future version of himself, shortly before the future versions of the other three Ninja arrived with the Golden Weapons of the past. After the Golden Weapons were used to destroy the Mega Weapon, Nya disappeared before Past Kai's eyes as history repaired itself.

The Last Hope
When Dr. Julien repaired the Falcon, the mechanical bird discovered that the Ninja and Misako were being threatened by Garmadon's Samurai Mech. Nya came to the rescue in the Power Drill, but Garmadon caught up in the jungle and tossed the drill around. After Lloyd disabled the Samurai Mech, Nya drove the Power Drill to the Celestial Clock, and watched the Ninja's search for the Helmet of Shadows' pedestal. Unfortunately, they were unable to stop the countdown in time, and General Kozu captured Nya while the others fell off the mountain.

Return of the Overlord
Nya was brought before Lord Garmadon and the Overlord, who were admiring the newly-completed Garmatron. Nya insisted that the Ninja would stop the dark weapon, but Garmadon laughed at her defiance before using her as a test subject for the Dark Matter he intended to use against Ninjago. Corrupted by the Dark Matter, Nya became a loyal servant of the villains, and was deployed against the Ninja when they attempted to pursue the Garmatron.

The Ninja stayed behind to occupy their corrupted friend, while Lloyd, Sensei Wu, and Misako continued to chase the Stone Army. Despite being outnumbered, Nya held the upper hand against the Ninja, as they were unwilling to hurt her with their elemental powers. However, Zane eventually realized that they could use their powers on the environment instead, leaving Nya trapped in a dome of ice while the Ninja moved on. She eventually broke free and reached the beach in time to join the Overlord's forces in passing through a portal to Ninjago City, leaving the heroes stranded on the Island of Darkness.

Rise of the Spinjitzu Master
From atop the Garmatron, Nya observed the Overlord's attack on Ninjago City. After the Overlord regained his true form and transformed the Garmatron into a massive fortress, Nya was stationed on a mobile turret on the outside of the building. She opened fire on Lloyd when he breached the outer wall, destroying his Golden Mech. When the Ninja arrived to support Lloyd, Nya destroyed an ice wall made by Zane, but retreated when Dareth took control of the Stone Army by donning the Helmet of Shadows.

When the Stone Army began climbing the tower, Nya shot them off the stairs with her turret. She also fired on the Ultra Dragon and clipped its tail with a shot, forcing it to land. Nya then returned to attacking the Ninja as they climbed the stairs, watching their numbers dwindle as the Overlord infected Cole and Jay with darkness. With Zane staying behind to fend off his corrupted allies, Nya confidently mocked Lloyd's chances of victory, but Kai destroyed her turret and engaged her in combat to allow the Green Ninja to reach the top of the tower.

Nya watched the final battle between the Overlord and Lloyd, who unlocked his full powers as the Ultimate Spinjitzu Master and defeated the embodiment of darkness. With the Overlord's defeat, the darkness infecting Nya's body and mind disappeared, returning her to normal just in time to hug Kai and a similarly-recovered Jay.

Appearance
Nya has short black hair fashioned in a bob cut, red lipstick, and small dimples on her cheeks. She typically wears clothing in various shades of red. In the show, she wears a large golden bracelet with a red jewel on her left arm. In the Spinjitzu Spinners game, she has a red bandanna tied around the lower half of her face.

Personality
Although she is not a ninja, she is very capable of defending herself. She doesn't like the fact that so much focus is put on the Ninja, so she resolved to become a hero in her own way, which she did by becoming Samurai X. Sometimes she gets annoyed by Kai's protectiveness, but their bond as siblings is strong. Many episodes reveal she is highly intelligent, as she was able to create the Samurai armor and technology, and she was able to pinpoint the location of Serpentine tombs. At first it seemed that Nya was unaware of Jay's crush on her, although by Once Bitten, Twice Shy it is revealed she returns his feelings.

Abilities and weapons
Despite a lack of formal Ninja training, Nya is a competent fighter, wielding a Nin-Jo against the Skulkin when they attacked the blacksmith shop. She also develops a talent for engineering and operating machinery, building her Samurai X gear and the Samurai Mech in her spare time without any of the others noticing and modifying the Ultra Sonic Raider to give it a flight mode. Nya also helped Dr. Julien construct the Fire Mech and the Earth Driller. She is a skilled pilot, being the de facto operator of the Destiny's Bounty and the Samurai Mech.

After being corrupted by Dark Matter, Nya displays the ability to perform Spinjitzu, creating a crimson energy tornado that can knock the Ninja around. She wields a spiked flail and sharp throwing needles in combat, and the evil suffusing her being has made her completely ruthless and willing to destroy her former allies.

Ninjago.com Description
Sister of Fire

Weapon of Choice: Double daggers

Elemental color: Red

Strength: Intuition

Make no mistake – this girl is no damsel in distress. She proved that when she and Flame the fire dragon helped rescue Kai from Lord Garmadon. And she's not one to take no for an answer.

Nya is fed up with the Ninja's boys' club syndrome and is determined to show everyone she can do anything they can do – only better. She trains hard to beat her brother's records, and Sensei Wu constantly reminds her that if she is patient, her time will come.

Trivia

 * Her favorite color is blue.
 * She is severely allergic to perfume.
 * It is revealed in "Double Trouble" that Nya has a part time job in the Auto Body Shop.
 * It was seen that Nya's Spinjitzu tornado is crimson, when her dark-matter infected state used it.
 * In The Invitation, Garmadon implied that Nya is descended from an Elemental Master, but she has yet to unlock such powers.
 * Nya's 2011 minifigure has two sides: a regular side and a side with a mask over her mouth.

Set Appearances
Normal: Samurai:
 * 2172 Nya
 * 2507 Fire Temple
 * 9566 Samurai X
 * 9448 Samurai Mech

As Samurai X
Samurai X is a character in the 2012-present lines of Ninjago. At first, not much was known about the character aside from her fighting against the Serpentine and helping out the Ninja on occasion, but in "The Snake King", it is revealed that she is Nya's alter-ego.

Appearance
Samurai X has a gunmetal samurai helmet, with a bucket handle piece on top in the place of horns and a red face mask. She also has gunmetal samurai shoulder pads with a red armor suit underneath. In the show, she wears a pair of goggles over her eyes and her bracelet on her right arm.

Ninjago.com Description
Strong, silent, super swift

Like a phantom exo-suit-clad giant, the mysterious Samurai swoops in from who-knows-where and beats the Ninja at their every step. Is he friend? Or enemy?

Despite their greatest efforts, the Ninja remain in the dark when it comes to the true identity of this masked renegade, whose only calling card is an "S"-shaped boomerang blade. One thing is clear - he hates the Serpentine, but will he turn against the Ninja to save himself, or unite with them to save Ninjago? Only time will tell...

Trivia

 * One early indicator of Nya's connection to Samurai X is found in the 9566 Samurai X set, with the minifigure having Nya's two minifigure faces. Likewise, an in-show indicator of Nya being Samurai X was her bracelet.
 * In the 2012 Ninjago.com description for Nya, she is wearing her Samurai X clothes.
 * Ironically, Jay seemed to hate the Samurai the most, even though he actually has a crush on Nya. He later accepts the truth calmly after he and Nya reveal their feelings for one another and he discovers her identity.