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This article contains plot details and spoilers for a current or future season.
Each villain held a customized weapon with a black hilt and a translucent green crystal at the bottom. Samukai held a Double-Bladed Bone Axe replica, Pythor held an Anacondrai Staff replica, Kozu held an Elemental Blade replica, Cryptor held a replica of Cole's Techno Blade, Chen held a Jadeblade replica, and Morro holds a replica of the Sword of Sanctuary. Each weapon was associated with the villain in some way - for instance, the Ninja wielded Elemental Blades while fighting Kozu and the Stone Army.
Dr. Saunders oversaw the creation of the Hall of Villainy. On the Day of the Departed, the Ninja stopped by the museum and were introduced to the exhibit by Dr. Saunders. The Ninja namely Kai and Jay, were made very uneasy by the exhibit and the statues inside. As Cole wanders further into the exhibit, he finds a painting of Yang and an artifact called the Yin Blade, which can cut open the fabric of reality. Saunders mentions that there are more statues to be added to the exhibit, including ones of The Overlord and the Golden Master. As Cole receives a message from Yang, the Ninja, Wu and Misako leave the museum, setting off to commemorate their ancestors. Cole realizes he's fading away, and goes to Yang's Temple to settle his debt.
At the temple, Yang tricks Cole into opening the Departed Realm, allowing the spirits of the Ninjas' old enemies to escape into Ninjago. The spirits travel through the city, heading into the museum and possessing the statues in the Hall of Villainy. Samukai, Kozu, Cryptor, Chen and Morro are resurrected, after which they confront one another. The five villains go to the painting of Yang, which he uses to send them a message, explaining that though he brought them to life they can only remain in Ninjago for the duration of the lunar eclipse, unless they kill the person that killed them. While explaining this, Pythor arrives in the museum, and he steals the Anacondrai Staff that his statue is holding.
Pythor joins the other villains as they speak with Yang, who tells them to choose an adversary to go after. Chen says he'll go after Kai and Nya, Pythor says he'll go after Lloyd, Cryptor says he'll go after Zane, Morro says he'll go after Wu, Kozu says he'll go after Dareth, and Samukai is left with going after Jay. After making their decisions, the villains go to the Hall of Sidekicks, where they gather reinforcements for their upcoming missions.
The villains set off to defeat their respective adversaries. Samukai, Kozu, Cryptor and Chen were all defeated a second time, with their spirits being sent back to the Departed Realm while their statues were destroyed. Morro, on the other hand, warned Wu of the coming attacks, which allowed him to reunite with the Ninja and head to Yang's Temple. Morro returned to the museum, placing the statue in the position it was originally in before peacefully returning to the Departed Realm.
It is unknown what will become of the exhibit due to the loss of the statues, though Pythor's and Morro's still remain mostly intact.
- According to Dr. Saunders, statues of the Overlord and the Golden Master would also go on display at some point, as they were yet to be unpacked and were still in the storage room.