you can all say as you wish about the theory. Yes its obviously not true, but you must give it credit for being THE most well-known theory on the net.
Actually, while the tengu theory is incorrect as a whole, the author of that theory did stumble onto a Tengu connection. Kishimoto uses the Tengu as symbolism for the Uchiha clan, more specifically Sasuke Uchiha. Just as he uses the Fox(Kitsune) as a symbol of Naruto.
The Fox(Kitsune), Tanuki, Tengu & Dragon are known as the Henge. You've heard the word Henge before right? That's right the Henge no Jutsu, got it's name from the name of the above shapeshifting kami from Japanese shinto/buddhist beliefs. Here's your proof:
There are two types of Tengu. The Konoha Tengu & the Karasu(crow) Tengu. Kishimoto specifically placed the two figures as statues outside of the fire temple prior to the attack of Hidan & Kakuzu. He didn't do this for kicks, he wants the reader to see underneath the underneath:
it might be well known but its retarded and invalid so it dosen't matter
SIG AND AVA BY JAIDEN
doesn't this theory say that the freaking tengu married an uchiha girl and that was how sharingan was created?? also that the tengu is madara's dad???.......for it to be true, only madara and his bro could possibly have sharingan!!!!!(and they don't have children) so, how does this theory explains the other uchiha having sharingan?????
Miau, Miau, Miau.....prrrrrrrrrrrrrrrr!!!!!!!!!!
What I can tell you for sure is that Kishimoto doesn't think this stuff up on the fly & he's had this all planned out from the very beginning. He might have made a few minor adjustments, but the overall outline for his story remains unchanged. He also plants several hints about future events all throughout the series. The words Kakashi said back in part one are very important, "A ninja must be able to see underneath the underneath."
personally, I find the tengu theory was nice and solid, but I think the mangaka is just using the folklore to add some creativity to the series... just like how we have fictions that borrow from european mythologies without actually involving them in the storyline. There is an anime amatsuki that actually has tengu characters and whatnot, but i think this mangaka is just about subtle references.
TENGU THEORY IS NOT VALID TO NARUTO!!!!!!!!!!!!!!!!!!!!!!!!! kill this please
SIG AND AVA BY JAIDEN
I second that....
It's all a subtle reference to the mythologies and such, same as with the 8-headed snake, kitsune, the crow, sussanoo, etc... It's all based on something else. Fair to say the Tengu being Madara's father was a bit off but there is a connection between as its not only outside the Fire Temple but also one of the Uchiha hideouts that they are shown. There might be a connection there Uchiha-Fire Temple.