Airdate: October 29, 2016
On a special holiday known as the Day of the Departed, Ninjago’s citizens honor departed souls. Jay visits his parents, and Kai and Nya remember theirs. Lloyd and Misako go to the Corridor of Elders to remember Garmadon, while Sensei Wu remembers his father and Zane remembers his. Meanwhile, Cole feels self conscious about his ghostly appearance. He goes to Yang’s Haunted Temple to repay a debt, but Yang wants something different – this year is special and there will be a lunar eclipse which will be his only chance to bring back passed villains. Yang tells Cole that if he does not help him by the lunar eclipse, he is doomed to remain a ghost forever and even may fade away forever.”
Takes place between the events of Skybound and Hands of Time.
- Back from the Dead: Samukai, Kozu, Cryptor, Chen, and Morro all return from the Departed Realm by possessing mannequins, but Yang tells them that they have until the end of the eclipse to kill one of the Ninja and take their place among the living, or else they will be sent back to the Departed Realm. The former 4 villains are felled in battle while Morro instead chooses to warn Wu and the Ninja about Yang before returning to the Departed Realm willingly.
- Bait-and-Switch: Morro tells the other villains that he is choosing Wu as his target and his confrontation with his old teacher makes it look like they're about to battle. Instead, Morro actually warns Wu about Yang's scheme and chooses to help him and Ninja instead, before he parts with his mentor on good terms.
- Billions of Buttons: When Master Chen was first resurected by Yang, his first action is pressing all of the buttons available on his chair, just for the fun. Ot happens again when he brings the Chenosaurus to fight off agaisnt Kai and Nya... just for one of the buttons to bring up something useles, and he tries to find the correct button to bring out anything that can destroy the ninja. Nya and Kai gave a small laugh during this.
- Continuity Nod: When Pythor joins the other villains in getting revenge on the Ninja, he greets Cryptor with enthusiasm and calls him a loyal friend since they served the Overlord together. But when he sees Chen again, both greet each distastefully, Pythor because he hates Chen for starting the Serpentine War and dishonoring the Anacondrai Tribe's memory, and Chen because Pythor played a part in his banishment to the Cursed Realm.
- Comically Missing the Point: When Kozu tells Dareth "Revenge will be mine!", Dareth thinks that it actually is a song request, since The Royal Blacksmiths somehow have a song named like that.
- Earn Your Happy Ending: After spending the previous two seasons as a ghost, Cole is restored to his original self, but with a scar on his forehead.
- Fictional Holiday: Day of the Departed is roughly similar to either Día de las Muertos or Halloween.
- Foreshadowing: Dr. Saunders, an "ally" to the Ninja, is oddly excited about the Hall of Villainy and the villains that nearly destroyed them.
- Heel–Face Revolving Door: Pythor goes Heel again and allies with the revived villains.
- It's Personal: Kozu has it out for Dareth using the Helmet of Shadows on him and his troops during the first final battle with the Overlord.
- Menacing Museum: Being based on the ninja's previous enemies, the Hall of Villainy naturally has a fearsome atmosphere, and on the tour, the ninja remark on the uneasy feeling they get from the statues.
- No-One Could Have Survived That: When Pythor jumps off the statue after being cornered by Lloyd and Misako, the former asks the latter if he's gone for good, but Misako says that Pythor is as much cat as he is snake, stating he has nine lives. Pythor does indeed survive the fall, but the fact that he's limping away afterwards proves that the impact was quite painful.
- Sole Survivor: Pythor is the only villain who comes out of his confrontation alive by choosing to pull a Villain: Exit, Stage Left. Justified, as unlike the other villains, he's actually still alive and wasn't summoned from the Departed Realm, so he isn't on a time limit to kill Lloyd.
- Tempting Fate: Kai and Nya wonder if they'll find out what happened to their parents. The fate of their parents becomes a major plot point in the next season.
- Token Good Teammate: Morro is the only resurrected villain who doesn't attack his target and instead helps the ninja. He's also the only villain who actually returns to the Departed Realm willingly.
- Villain: Exit, Stage Left: After being defeated by Lloyd and Misako, Pythor jumps off the statue he's on to make a "spectacular get-away". He ends up hurting himself greatly from the fall and is last seen limping away.
- Villain Team-Up: Samukai, Kozu, Cryptor, Chen and Pythor team up to get revenge on the ninja.
