Background :

In Ninjago Season 10: March of the Oni concludes the Oni Trilogy storyline, which began in Season 8, with the arrival of the Oni in the Realm of Ninjago. The Oni, known as the "Bringers of Doom," are a race of powerful, ancient demons from the First Realm who seek to cover all Realms in darkness and destruction.

Oni's Final Battle - Season 10

Season 10 Preview:

Their Leader is the Omega, a powerful Oni who commands the Power of Destruction and showcases tremendous strength and agility. The Oni invasion begins as a black cloud that spreads across Ninjago City, petrifying anyone it touches into a stone figure. The Ninja quickly discover their Elemental Powers are ineffective against the dark cloud and are forced to retreat to the rebuilt Monastery of Spinjitzu. In a desperate attempt to stop the invasion, Lloyd and Lord Garmadon venture into the darkness to destroy the Realm Crystal, the source of the Oni's entry into Ninjago. Inside Borg Tower, they face the Omega, who easily overpowers both Lloyd and Garmadon, mocking Garmadon's desire to be more human. After escaping the Omega, the Ninja retrieve the Golden Armor and Kai reforges it into the original Four Golden Weapons, their final hope for victory. The climax features a Final Stand at the Monastery of Spinjitzu, where the Ninjas, Wu, Garmadon, and Faith unite against the Oni horde. Recognizing that individual strength is not enough, the Ninja, Master Wu, and Garmadon form the Tornado of Creation. The pure energy of Creation enveloped the Omega and the entire Oni Army, causing them to disappear and saving Ninjago from permanent darkness.