Here is where we post purposefully bad idea's for crossover fanfiction :)
Jack Sparrows Epic Adventure
While raiding a treasure island, Jack Sparrow finds a magical mirror, which transports him into Wonderland. He has come at a time where the Red Queen has been killed, and a war is wiping everything out. While Voldemort had been killed in another world, he left one special Horcrux in Wonderland. A Super Horcrux. Every other Horcrux that was destroyed sent it's piece of Voldemorts soul into the Super Horcrux.
What's the Super Horcrux? The One Ring. So Sauron/Voldemort has begun his conquest of Wonderland. The Mad Hatter, who is a wizard and has Sephiroth's sword, teaches Jack Sparrow magic, and they leave to face Sauron/Voldemort. But they have to cross Scorpions Bone Pit, and only one guide can safely show them through...