The Forgotten Element

The Forgotten Element is the 7th episode in the fourth season and the 41st overall in LEGO Ninjago: Masters of Spinjitzu.

Plot
In the Anacondrai Temple, Kai, Jay, Griffin Turner, Neuro, Paleman and Shade are being led in chains made of Vengestone to have their powers taken away. As most of the Masters lament on the situation of not teaming up sooner, Jay attempts to keep a positive attitude, still confident that Lloyd'll save them. Upon being brought before Clouse and Skylor, Kai questions how she could help her father knowing he'll need her element for the spell. Saying she had no choice, Kai asks who planned to have him fall for her, which surprises Skylor. Chen arrives via Gravity-defying throne, happy with the decor and that he'll have more elements in his Staff. Jay states his belief in Lloyd, which Chen doubts but waits a few seconds to see if he's right. Getting bored, Chen raises his Staff and takes the Masters' powers. Upon Chen ordering for the Masters to be sent to the factory, Skylor begs for Kai to be spared saying he can help them which he complies with.

Outside, Lloyd, Nya, and Garmadon are near the entrance to the temple. Nya realizes that they'll have to wait until nightfall due to the amount of grunts, though Lloyd protests. Garmadon comforts his son, and says that real power empowers those around him.

Meanwhile, the cultist guards observe Eyezor and complain about his General status. Assuming they need names, they dub themselves Kapau and Chope (the latter choosing it due to his original choice of Maleficium being too difficult to pronounce) only to be shouted at by Eyezor.

In the factory, Jay is set to work and soon spots Cole and Zane, who he's impressed with due to his new form. Cole explains the guards think he and Zane escaped and their progress on the roto jet, while the guards assume Karlof is fixing a noodle machine. Upon asking where Kai is, Jay states he's receiving special treatment.

Chen shows the Red Ninja his trophy collection (containing parts of the Ninjas' past adventures), though Kai responds that without the Staff, he'd strike the villain down. Chen explains that unlike Kai and Skylor, who got her powers from her mother, he himself had no abilities and was told he'd amount to nothing. He then shows Kai a portrait of Arcturus and announces with Lloyd's power, he'd be unstoppable. He then tells Kai he knows he's still jealous Lloyd became the Green Ninja and offers to give him the power he wanted to try for so long. However, Kai refuses to betray his friends: Chen counters this by promising dark secrets about his parents his senseis never told him. Clouse comes to tell him of Lloyd initiating his plan soon and they leave Kai to consider his offer.

The three refugees sneak into the palace unnoticed, though Lloyd sets off a trip wire and the trio is soon surrounded by cultists. Nya decides to hold them off while the Garmadons go only to encounter Clouse. Lloyd is forced to leave his father behind and falls into another one of Chen's trapdoor into a cave made by Clouse's serpent. Kai appears and gets the Green Ninja out and advises him of the situation and plan, but Lloyd refuses and says he needs to face Chen. With that, Kai blows out his torch and leaves while Lloyd finds himself with Chen in the throne room. Shocked that Chen managed to turn Kai against him, Lloyd proceeds to battle while trying to talk some sense into Chen. However, the man uses everyone's elements to overwhelm the Green Ninja and defeats him.

Nya wakes up in the dungeon of the snake where, along with Garmadon, she's chained to a post. Chen, Clouse, and Skylor approach and inform them of Lloyd's defeat and that his power will be taken soon. Nya questions how they were able to defeat him to which Kai enters, saying Lloyd never stood a chance alone. Garmadon, now enraged of Chen turning the Ninja against each other like he did to their ancestors, grabs Skylor and threatens her unless he and Nya are released: they call his bluff due to his reform and he's forced to release the Orange Ninja, shocked with her father. Clouse opens a tunnel door for his snake to enter after its nap while Nya tries to talk sense into her brother. As everyone leaves, Kai winks at them, revealing he only pretended to switch sides to gain Chen's trust. As Chen and Clouse leave to prepare for the ceremony, Kai pulls Skylor back and explains he can get the Staff. Skylor asks why he'd tell her after her betrayal: Kai states she let him go for a reason, with her feelings for him being the most obvious choice which she admits.

Back in the factory, Jay is working on the roto jet when Karlof signals the Ninja of Zugu approaching. Zugu tells them of the feast celebrating the Green Ninja's defeat and that they need noodles for it. Upon removing the sheet, they realize the truth while Cole jumps in and begins firing. However, the blaster overheats while the Masters turn the Jet to fire while Karlof continues work on getting it to fly. Firing two missiles, they make an opening and push the jet through.

The ceremony begins and Lloyd is brought in by Kapau and Chope. Lloyd questions why Kai would betray him, though he tells him not to worry. Chen then has Skylor give up her powers.

In the dungeon, the snake is close while Garmadon assumes his karma for destroying the Great Devourer has caught up to him. Just as the snake is about to eat Nya, the Masters crash through the wall with the roto jet and shoot the ceiling, crushing the snake with rocks. Nya soon hugs Zane in joy while Cole encourages Karlof on completing the jet.

By now, Skylor has completely lost her power and Chen proceeds to take Lloyd's Energy. As Clouse begins the spell, Kai tells Chen he forgot one element: surprise. Skylor then kicks the Staff out of her father's hands and Kai uses it to free Lloyd, hold off the cultists and freeze Clouse. Lloyd tells him to destroy the Staff, but Kai begins to become corrupted by its power. Just before he uses it on Lloyd and Skylor, everyone busts in and attack, causing him to drop the Staff. Kai grabs the Staff before Chen does and destroys it, restoring everyone's elements and captures the cultists. Then, Lloyd, Kai, Jay, Cole, and Zane all reunited, doing Spinjitzu, forcing Chen, Clouse, Eyezor, Kapau, Chope, and Zugu to escape with Skylor now their prisoner.

With the Elemental Masters now in control of the island, Nya and Garmadon assure Kai they'll find the remaining cultists and rescue Skylor while Kai expresses surprise at finding an old friend and making new ones.

Trivia

 * The Tournament of Elements ends with Chen the self-proclaimed winner, even though he is not an Elemental Master of any kind. Thus, Lloyd would have been the technical winner.
 * Chen would most likely consider himself as the winner as a "hidden" contestant in order to manipulate the Elemental Fighters into his real plans; he could have also declared the powers in the staff as his own, as Chen loves to be named the most strongest warrior and would dislike the idea to think he is powerless.
 * The Boulder Blaster makes its debut as the completed Roto Jet.
 * Among Chen's trophy collection was a scale from the Great Devourer, Captain Soto's peg leg, a cog from the Celestial Clock, Zane's pink gi, Skales's snake king crown, the Blade Cup, the Green Ninja prophecy, Stone Armor, and an Anacondrai sword.
 * Chen's statement that he "decided when the war is over" is proven to be true later in episode "The Greatest Fear of All," due to the fact that he started the war to begin with.
 * According to Chen, there were secrets about Kai's parents which made him betray the Ninja (partially). However, it's unknown and unclear what he knew about them which made him bribe Kai to capture the Green Ninja for the spell to be complete. It is also unknown if he actually knew anything about them in the first place.
 * Garmadon mentions that he killed the Great Devourer in "Day of The Great Devourer."
 * It was shown at the end of "Can of Worms" that Lloyd cleaned Zane's gi after washing it 20 times. However, a story in the Ninjago webpage states that Master Chen, or some of his men, must have snuck onboard the Destiny's Bounty and replaced the gi in the washer with a completely white one.
 * Once the Elemental Masters secured the palace, Zane did his 'funny dance' for his friends. This may have been to show them he was the old Zane they knew so well under his new look, since the only other time he did so was his self-discovery as a robot.
 * When everyone is cheering for Cole after he blasts the door, Jacob can be seen cheering with them behind Bolobo.

Errors

 * Even though Captain Soto's peg leg was in Chen's trophy collection, Captain Soto was seen with his peg leg in "The Greatest Fear of All." He may have just gotten a replacement.
 * After Chen absorbed the powers of the Elemental Masters, Paleman still remained invisible.