The Keystone Wardens are a group of elemental constructs summoned by the Shredder's Heralds as a means of preventing the Turtles, Splinter, Karai, and the Ancient One from activating the Keystones. Each warden is able to manipulate a natural element: Fire, Wind, and Water.
- The Keystone Wardens each fought the Turtles, Splinter, Karai, and the Ancient One at different locations:
- The Fire Warden fought Leonardo, Karai, and the Ancient One at the Statue of Liberty.
- The Wind Warden fought Raphael and Michelangelo at Manny's Meats.
- The Water Warden fought Donatello and Splinter at the United Nations Building.
Utilizing the skills taught to them by the Ninja Tribunal and their new powers, the three groups manage to defeat the Wardens and take control of the Keystones. However, when Shredder Tengu learns of this, he uses his even more powerful magic to regain control of the Keystones.