Bender of Fire and Lightning

"Our world has long existed in parallel with others, unseen just beyond the veil of space-time. Like both our closest neighbors, we had an avatar that controlled the four elements and sought balance with the spirit world. 100 years ago our Avatar went insane: though he killed a great many people himself before he was slain, his biggest crime was the release and maddening of the Nine Great Tailed Spirits. The tailed ones ran rampant for years before the technique for sealing them in human vessels was learned and used to control the beasts. The tailed spirits became the weapons of the great Ninja villages, causing much heartbreak and strife that continues to this day.

"Meanwhile, the spirit of the Avatar continued to exist, though not as he had been. Slain while in transition to his deadly Avatar form, the last Avatar's spirit did not re-enter the stream of reincarnation as it normally would but instead split into many parts, each representing one of his many incarnations. The parts scattered, attaching themselves to various members of the group that killed the maddened one. Those fragments still exist, jumping from host to host like passive ghosts sharing a person's shell. A few times a great number have managed to attach themselves to a single person, increasing that person's luck, insight and abilities in various ways, perhaps by direct communication similar to the old Avatar's ability to call on his past lives' experiences. However, those hosts inevitably attract the attention of the tailed beasts and usually die messily shortly thereafter. (The fourth Hokage of Konoha is a notable example)

"Now, a group of madmen and criminals plots to collect all of the Tailed Beast Spirits into a single place and use their power to control the world; already many of the Hosts have been slain and their spirits extracted. An evil Genius (formerly a member of the first group) has achieved a limited form of immortality by mimicking the soul-transfer process the Avatar spirits use to survive, though for most sinister purposes. The carrier of the Maddened Avatar's spirit fragment has already slain all but one member of his clan and joined the group of criminals bent on world domination.

"An old power has been rediscovered and perfected, allowing travel to and from the dimension beyond the spirit world, where a young but sane Avatar lives. To redeem myself and save the best friend I abandoned years ago, I prepare to embark on a new quest in a completely unknown land, seeking the Avatar..."

-from the journals of Sasuke Uchiha, Bender of Fire and Lightning

Prologue to Yet another fic I will probably never write! I don't know the Avatar storyline well enough to tell it, but the idea of Sasuke and Zuko teaming up to look for the avatar (for very different purposes) caught my imagination. (We'll show him to your father, then I'll take him to my world. Its mutually beneficial.) In my head Sasuke leaves for the Avatar world after his fight with Deidara, leaving team Hebi to deliver a letter to Naruto and Sakura, and to help with the search for the various peices of the naruto-verse's Avatar spirit... but anyway... If you adopt this story spark, please please please tell me, I'd love to read it!