Background :

The Ninja, having grown lazy during a time of peace, search for a new adventure. Explorer Clutch Powers, discovers an ancient pyramid, leading the Ninja to a new quest. Inside the pyramid, the Ninja accidently release the imprisoned Serpentine sorceress, Aspheera. After imprisoned for millennia, Aspheera immediately steals Kai's, Elemental Powers and uses them to revive an ancient army of mummified Serpentine.

Pyro Vipers

Season 11, Fire Chapter Preview :

This army, included Char, the Pyro Slayers, the Pyro Whippers, and the Pyro Destroyers, who are all known as the Pyro Vipers. Aspheera also uses Kai's power to create a giant snake, Fire Fang, to serve her. She seeks revenge on the "Treacherous Deceiver" who imprisoned her a thousand years ago. The Ninja interact with Clutch Powers, again at the hospital, where he reveals the location of the Second, Scroll of Forbidden Spinjitzu. Master Wu eventually confesses that he is the "Treacherous Deceiver," explaining he once befriended Aspheera and taught her Spinjitzu, which she used for evil. The Pyro Vipers, led by Aspheera and her servant Char, attack the Monastery of Spinjitzu. The Ninja desperately defend the Monastery and Wu from the Pyro Vipers, with P.I.X.A.L.'s help and using the Second, Forbidden Spinjitzu Scroll. In the final battle, of Season 11, Zane manages to defeat and freeze Aspheera, leading to her capture and imprisonment in Kryptarium Prison. However, Aspheera manages a final blast with the Scroll, banishing Zane to the Never-Realm and setting up the plot for the Ice Chapter.