I think Obito could've killed her by accident.
Somehow manipulated Kakashi's actions by using a connection of some sort; maybe Zetsu's Senju powers interacting with the sharingan to create a flash of a Rinnengan technique? Was Kakashi a temporary path?
Im not really the thread posting type but it's a "Tobi Topic" so I couldn't help myself and hopefully this thread will inform those who truly doubt that Izuna is indeed in fact Tobi.
Tobi is Izuna Uchiha beyond a shadow of a doubt (I could be wrong if Kishi uses his ninja art troll no jutsu)...
A second ago I had a thought & this thought turned into a question .. Let me get straight to the point.
During the battle between Minato & Tobi, Tobi is marked with the seal of the "Flying Thunder God Technique" (As shown below).
My question is .. Is this marking permenanent?
If it is then...