Oni Mask of Hatred

The Oni Mask of Hatred was one of the three Oni Masks. When worn, it turned the user's entire body into invulnerable magma stone, making them invincible to all forms of damage.

History
At some point in time, the three Oni Masks were created in the Realm of Oni and Dragons by the Oni. They would eventually end up in the realm of Ninjago through unknown means, with the Oni Mask of Hatred being sealed away within the Oni Temple deep within Primeval's Eye, presumably by the Oni themselves.

Game of Masks
Lloyd and Harumi manage to locate the Oni Mask of Hatred within the Oni Temple. Harumi attempts to grab it, but a force makes it so she cannot. She then explains to Lloyd that someone with Oni blood can obtain the mask. After Lloyd takes the mask, he soon begins to question Harumi on how she knew that he was part Oni. After a moment of revelations, Lloyd discovers Harumi's true intentions and realizes that she is the Quiet One. A fight then ensues, with it ending with Lloyd throwing the Oni Mask of Hatred over the side of the platform. However, Harumi dives after it, catching it while she manages to use her knife to hold onto the side of the platform.

Armed with the Oni Mask of Hatred, Harumi puts it on, using its powers to jump back onto the platform. Lloyd questions what the mask did to her, where she reveals that it has made her invincible to all forms of damage. After a very brief fight, Harumi reveals to Lloyd that she wants him to feel the pain she has felt following the death of her parents by having Lord Garmadon destroy Lloyd. Harumi then proceeds to flee from the temple with the mask, utilizing her invincibility to destroy the temple in an effort to destroy Lloyd.

Harumi would later escape with her fellow Sons of Garmadon members with the three masks during the midst of the battle against the Sea Monster.

Dread on Arrival
Ultra Violet uses the Oni Mask of Hatred to fend off the Ninjago police force during their attack on the Royal Palace, which was taken over by the Sons of Garmadon and coverted into the Temple of Resurrection. The Oni Mask of Hatred would later be used in the resurrection ritual with the other two masks. However, the Ninja would stop the ritual before it could be complete. The Ninjago police force soon arrives, arresting the Sons of Garmadon and presumably confiscating the masks.

Big Trouble, Little Ninjago
At some point, the Oni Mask of Hatred would be recovered by the Sons of Garmadon. Harumi would use the mask after she confronts the now powerless Lloyd and Toddler Wu on a rooftop. She would continue to chase Lloyd while using the mask's powers to her advantage. Eventually, Harumi confronts Lloyd on a monorail, but Lloyd was able to throw Toddler Wu to the Ninja on the Bounty, who were then forced to use the Traveler's Tea that Mistaké gave them earlier to escape to the Realm of Oni and Dragons after Garmadon's Colossus beast destroys the Bounty. After Lloyd escapes Harumi with Nya, Misako, and P.I.X.A.L. in the same fashion Mr. E did prior, Harumi takes off the mask while angrily looking towards Lloyd.

The Gilded Path
Harumi used the Oni Mask of Hatred during a S.O.G. raid on The Resistance's HQ. She used the mask in an attempt to battle Lloyd but was stopped by Skylor. When Skylor attempted to remove the mask, Harumi quickly stopped her. As Harumi was about to capture Skylor, Lloyd and Nya saved her by ramming Harumi with an armored car, but she survived due to the Oni Mask of Hatred she wearing at the time.