The Mask of Power is an evil, dangerous artifact, and the title object in the Skylanders: Mask of Power series.
The Mask of Power was created millennia ago by a guild of Spell Punks for their king, Nefarion, a follower of The Darkness who wanted to destroy the Core of Light. Combining their powers, the Spell Punks conjured up the Mask which is said to be able to tap into the eight Elements: Fire, Water, Earth, Air, Life, Undead, Magic and Tech. No one knows what the Mask of Power does, but Nefarion had tried on the Mask, which triggered catastrophic events such as The Forest of Life being set ablaze, the oceans boiling away to nothing, trolls attacking every village in Skylands, and zombie sheep going on a woolly rampage.
With the Mask's power, the king was able to enslave all of Skylands with ease for hundreds of years. He was eventually defeated, and the Mask of Power was broken into eight pieces, which were hidden across Skylands by the remaining Portal Masters of Old so that they could never be found.
Years later, Kaos sought to find the fragments to reassemble the Mask of Power and use it to destroy the Core of Light. Despite the Skylanders gaining most of the pieces before the evil Portal Master did, Kaos was able to steal them and rebuilt the Mask of Power, using its power to steal the abilities of the Skylanders and wreck havoc across Skylands. When he attacked the Core of Light, Kaos was tricked into attempting to harness the Skylanders' powers all at once, which caused him to lose control. During the confusion, the Skylander Trigger Happy yanked the Mask of Power off Kaos' face. The removal of the Mask restored the abilities of all the present Skylanders, who then ultimately destroyed the evil artifact with their combined powers.
When worn, the Mask triggers catastrophic events across the land, and transforms the wearer into a tall, slender beast with a mane of venomous serpents, granting them terrible powers and abilities. It not only allows the wearer to use all of the powers of the Elements, it also steals the abilities of Skylanders. One other ability is that the mask makes the wearer immune to age allowing Nefarion to rule for centuries.