for those of you who dono the theory, here's the link
The Dark History of Uchiha: The Bloodline of Tengu <SPOILERS WILL GET YOU BANNED> - Naruto Forums
then what would you call it? if there WAS evidence then that doesnt make it a theory -_-... of course it hasnt been proven, thats why its just a theory, a speculation.I'd like y'all to stop calling it a theory, since it is based on very limited evidence and has not been proven, so it's a hypothesis and at best hypothetical theory (yikes). It's safe to say this is put together the few tengus drawn in the manga to back it up, an active imagination and some quick reading.