Tobi is left for dead orochimaru stumbled upon tobis body and sees a valuable research subject so decided to take him back to his lab and experiment with him. Orochimaru at the time was experimenting at the time he creates white zetsu and fuses it to a child later know as black zetsu them two will now become zetsu.The white zetsu is made from the firsts dna. Orochimaru seeing this as a success decided to fuse part of obitos body which had been damaged by the boulder with white zetsu this will explain the firsts dna and the ooze from his limbs. So him and zetsu over time become friends and then one day orochimaru is found out and decides to flee the village with zetsu and obito leaving yamato behind. obito and zetsu escape and stumble upon a dying madaara. Madaara teaches obito about the uchihas history and his moon eye plan he trains zetsu and obito he feels obito is ready and sends him to capture the nine tails he teaches obito what he needs to know on how to capture it and what to do. Obito now is 15 and has had a growth spurt so he is now much taller than he was and is now around average height and due to puberty his voice is broken so his voice is unrecognizable anyway after a failed attempt to capture kurma he goes back to maadara and they begin to plot a plan. Maadara and obito decided to use nagato as a pawn in their plans making sure nagato gets rinengan.Now you gotta ask yourself how could to ninka mistake two civillians for parents? Well obito probably cast a genjutsu on them which caused them to kill nagatos parents.The pain and shock of the event unlocked nagatos rinnegan and so is the journey of nagato begins. He probably made sure somehow prehaps he used the dog as a way for nagato to meet yahiko and konan and used it to lead them to a place where they would meet a sanin before making it kill itself before it could be trained by the high level ninja jiraya seeing pitty and maybe a little genjutsu help he decides to train the orphans. Yahiko is later killed and danzo and hanzo is responsible maybe one of them was being told what to do prehaps by maadara or obito now at this point I think that prehaps obito is not the first tobi and it was maadara obito probably to the role of tobi a couple of times. anyway yahiko decides to make the akatski with the purpose of capturing the tailed beasts maadara dies and obito by surpassing his master and now becomes the new tobi. This brings us up to date to current events.
obi was crushed by a boulder there is no coming back how can he live from that? from that. We have seen alot of serious injuries in naruto over the years the rasengan which is an s class jutsu naruto has used countless of times on people and they have managed to survive so its possible he could have survived a boulder and even if he was killed he could have been easily brought back I mean look at chiyo she brought back gaara orchimaru could have found a technqiue able to revive him or something. Tobi is way to young explain how he could have matched minato? Itachi achived ms and age 12. He slaughtered the entire uchiha clan. If he can do that at age 12 matching minato at age 14 or 15 is very possible How do you know zetsu is one of orochimarus experiments? His zuzuzu matches the one that when yamato used on of his wood style in a manga chapter we know he got wood style from senju so its possible zetsu had some senju in him but has affected him differently.
Points I would like to make. Tobis skin on the left side of his face is extremely sagged this is caused when he was crushed by the boulder not all age if you look at other old characters you will see they dont have wrinkles like him.
In one of the naruto card games it says that zetsu hometown is konoha which supports my theory of him being fromt here and getting experiments by orchimaru.
His original left eye was gone the first time he appeared since when he uses his space time jutsu he only uses it in his right eye.
Being a uchiha he can support the rinnengan.
His space time jutsu is very similar to that of kakashi but since the eye is originally his the eye is perhaps limited in kakashi and it being his he has more control over it.
He was a student of the fourth who was a master of space time jutsu he could have easily picked up some knowledge from him.
Also I got one more thing that also proves my theory. If maadara was the first tobi and itachi knew then maybe when he said maadara was a former shadow of his self it wasnt maadara but prehaps obito who would obviously seem weaker in comparison? Yes itachi would be able to see the chakra change but maybe they did something to obito so his chakra would be like maadaras? Also he seems to have a huge lab so prehaps he got most of this from orochimaru. and the scroll suigetsu found prehaps has information about this?
There are a few holes in this theory but it makes sense
folks I have one theory Tobi is using
Obito's body like he did in Madara's
body when he control that 4rd mizukage(its surely
madaras' body cause at that time only madara
can use that tsukoyomi-thingy) when the 3rd ninja
war happened but that time madaras body getting
older so he need another body to control,so he
used the body or eye of obito(im sure its
obito,that explains why kakashi awaken his
mangekyo sharingan) but the time when itachi
killed the uchiha clan, I dont know if who's
body he is using at that time.
who he really is?hmmmmm,I guess he's Raikudo
Sage's First born son.Well, he knows
everything in the past,He knows about Raikudo,He
knows about the tailed beast and He is the only
one knows about The Moon Eye Plan(the Jubi).And he
convinced Nagato to build the group known as