Tobi wields the Makengo Sharingan.
Tobi is obito. obito gave kakashi his left eye on there last mission together, just before he died.
After Konan died Madara (Tobi) found Nagato's body and he transplanted Nagato's rinnegan into his left eye.
Tobi is not in one eye, but possess something very awesome so don't read on if you dont want me to spoil it................................... Tobi's is really Madara Uchiha (one of the 2 founders of the hidden leaf village (konoha) his eyes are really the Sharingan .
Tobi (Madara Uchiha) uses the sharingan on his left eye. Some people think its obito because his sharingan is on his left eye like kakashi, but kakashi has sharingan on the right side.
In the manga yes, the Sage of Six Paths was the first to wield it then Madara Uchiha then Nagato and then Tobi who stole one of Nagato's eyes. In real life however no it is not real.
_____Spoiler_____ Pein is the "leader" of the Akatsuki. But the founder of it was Madara, who is Tobi. Many people think Tobi is Otobi because of his eye, but he is not. Otobi was clearly killed. ~Lexi
Tobi is not Madara Uchiha. He is Obito Uchiha, whose right eye is his original Mangekyo Sharingan eye. His other eye is the eternal one, considering he can evolve it to the Rinnegan form, it's most likely to be one of Madara's.
Tobi is a character from the manga and anime series Naruto. He is typically depicted as wearing a mask with a single hole for his right eye, covering his left eye with his hair. He is often seen wearing a black cloak with red clouds on it.
I believe that Tobi has his own body "reserved" with his two sharingan Jutsu and he's been wanting Nagato to resurrect it at a certain time...But since Nagato died he was very disappointed. But now, he's using Obito's for the mean time thus the one eye and the similar dimensional jutsu like Kakashi's Mangekyou. I believe this real body is reserved to wield all the tailed-beast power...What do you guys think.
Tobi is MADARA UCHIHA. OBITO IS DEAD!!! HE WAS CRUSHED UNDER A ROCK!!! HE IS GONE FOREVER!!!!!Different person: I think Tobi is Madara and Obito. . .he is three in one! Why else would Tobi only have one eye! He gave his other sharingan to Kakashi. They wouldn't just bring up some random Uchiha and then just kill him off in his second episode. He has a perpose other than giving Kakashi his eye. . .right!Tobi in mandara ,obito is dead, the reason Tobi clothes is half armor is because he has deep wounds from the battle with Hashirama Senju and he still has is eyes but lost one by using inzagi to much from the battle with konan after konan got defeated but not killed Tobi went to yahiko and nagito grave to get the rinnegan and now his left eye is the rinnegan and right is sharingan. :) the first answers got pwned.
I am positive it is Tobi
Tobi because nobody could defeat him. But i think if naruto fight Tobi Tobi will get kill