Zankou, an extremely powerful Upper Level Demon was considered a threat to all magic. He was imprisoned in the Underworld for attempting to overthrow the Source and become ruler of the Underworld. He was later released to inflict chaos on Earth, and to disrupt good magic.
He is more powerful than any other demon, with Shax (The Source's personal assassin) being the only demon who comes close to his destructive abilities. He is also highly intelligent, conniving and deceitful. Zankou can acquire the powers of different magical beings, by killing them.
He has helped the Charmed Ones fight against the Avatars, when they mutually realized that the idea of Utopia created by the Avatars would wipe out demons entirely, as well as all free will of every other living creature. After they defeated the Avatars, Zankou went back to his very wicked ways and terrorised the Charmed Ones. Zankou continually attempted to steal the Book of Shadows, succeeding once. When he attained the Book of Shadows he was able to use a potion inside the book to steal Phoebe Halliwell's and Piper Halliwell's powers.
When Zankou took in the Nexus, the Charmed Ones destroyed it by casting a banishing spell, which vanquished Zankou.
Zankou was portrayed by Oded Fehr in 7 episodes of the 7th season of the CW's "Charmed".
It was hinted that he had a fling with the seer, Kyra, which is why he was raged by her betrayal to the side of good.
Powers and Abilities
Known powers that Zankou possessed include: Power absorption, Energy blasts/balls, Fire Balls, Teleportation( Flaming and Fading), Telekinesis, Pyrokinesis, Immortality, Conjuring Summoning, Sensing, Spell Casting, Super Strength, Regeneration, Shapeshifting, Resurrection, Premonition (stolen from Phoebe Halliwell), Molecular combustion / Molecular Immobilization (stolen from Piper Halliwell) and Demonic Projection.