Similarly, Morro is the only revived villain to not seek vengeance, but instead redemption and forgiveness. This is likely due to the concluding events in "Curseworld, Part II" when he realizes the true meaning of being the Green Ninja. His claim of having "unfinished business" with Wu in front of the other villains was a ruse to hide his true intentions of helping the ninja.

Tommy Andreasen stated, "We could either do a special or nothing. That's what time and money allowed." [23] Cole was the mascot ninja, and the promotional and box art was approprietly focused on the Crashcourse Canyon. The collectible items were the Departed Blades, except the Sword of Sanctuary. The sets mostly consisted of ninja vehicles. 70751 Temple of Airjitzu was released as part of the Possession wave over a year before "Day Departed" aired. However, it ties into the story of the special, as the set depicts the ninja using the Temple of Airjitzu as a base which happened at the end of the special after the temple returned to its original state. Before the special was released, Tommy Andreasen responded that "Yang only invites bad guys to the party" when asked if Garmadon could return on the Day of the Departed. [27] However, this statement proved to be false when Morro revealed himself as an ally to Wu and the ninja. When battling Yang's students, Cole says, "This isn't a fair fight. I'm handcuffed. [...] So you might want a few more guys." This is nearly identical to his quip in " Enkrypted": when Soto pointed out that the other Kryptarium inmates had weapons while the ninja were handcuffed, Cole said, "Yeah. Sounds like it's almost a fair fight." In-universe, it makes sense that Cole would reuse this line, considering the events of "Enkrypted" took place in an alternate timeline that Cole does not remember. In addition, Garmadon's next appearance to affect the future of the timeline would be as a villain.

Wu gets a bad feeling as Morro confronts him, though Wu is pained at having to fight his former student again, he states that he won't hesitate to do it again. However, Morro reveals he really has no intention of revenge; instead he tells Wu of Yang's plan and they set off to reunite the ninja.

However, both Chen and Cryptor's original deaths were indirectly caused by their targets destroying a more powerful villain; Nya drowned the Preeminent, and Zane froze the Golden Master. Cryptor was destroyed inadvertently (first by him being frozen and shattered, then by falling out of a tree). Andreasen confirmed various other aspects of the special, including that Pythor would appear in the flesh [9] and the special would feature several locations from early seasons. [10] Samukai was almost victorious but got overwhelmed (first the Golden Weapons, then Ronin supported Jay).Pythor didn't die but he did slip away (first by Garmadon destroying the Great Devourer, then by jumping off a statue). Samukai, Pythor, Generals Kozu and Cryptor, and Master Chen served as the secondary antagonists of the special. On the Day of the Departed, the ninja hurriedly travel across the Sea of Sand, en-route to the Ninjago Museum of History. Upon their arrival, Wu reminds them of the holiday's significance: for remembering fallen ancestors and cherishing family. Dr. Saunders arrives, greeting Wu and the ninja before presenting the museum's new exhibit, the Hall of Villainy, which houses life-sized mannequins of the major villains fought by the ninja over the years, as well as a plaque describing the rare Yin-Yang lunar eclipse. Cole finds a painting of Master Yang, as well as the Yin Blade, which is on display. Cole calls out to Saunders and asks what the weapon is, but realizes nobody is paying attention to him. Cole hears Yang's voice imploring him to "close the circle." Realizing he's fading away as one of the departed, Cole takes the Yin Blade and sets off to face Yang. In actuality, Yang doesn't ally with the revived villains. He uses them to distract the ninja so they won't interfere with him opening the Rift of Return. This special focuses on Yang's conflict with Cole, while the return of the villains acts as a subplot. Morro accepted his fate (by letting the Preeminent take him down and by returning to the Hall of Villainy then to the Departed Realm).

This is the only Ninjago special released. However, The Island has been alternatively released as a special in some countries.This is the first episode to feature several villains at once, including Samukai (last seen in " Wrong Place, Wrong Time"), Kozu (last seen in " Rise of the Spinjitzu Master"), Cryptor (last seen in " The Titanium Ninja"), Pythor, Zugu and Eyezor (last seen in " The Corridor of Elders"), and Chen and Morro (last seen in " Curseworld, Part II"). Some of these villains have appeared within the last ten episodes of the previous season, while others, such as Samukai and Kozu, had not appeared in over forty episodes, which aired four years prior. P.I.X.A.L. had a cameo at the beginning of the special, before the introductory sequence to tie in with the effects of Jay's final wish in the previous episode. Misako, Dareth, and Ronin also made appearances in the special. Chen's New Chair · 2. Chair Play Chen · 3. Chair Up Chen · 4. Chairful What You Wish For · 5. Bad Chair Day