[Theory] One of the ones who know everything is Tobirama.

[sacmador]

As the title says it could be Tobirama because;
1) We don't know much about him, while he is a very important Senju.
2) Due to 1, there should be some explanations about him.
3) We just know that Tobirama uses water perfectly and space-time jutsu which is irrelevant now and that he is the creator of edo tensei which is useful.
4) Probably, Sasuke wants Edo Madara to be vanished as Itachi's last will.
5) We know Tobirama is sealed forever.
6) We know a scroll which can turn the waves in the war.
7) Due to 4,5, and 6, Sasuke revived Orochimaru to find 'the ones'.
8) Probably, Orochimaru does not know edo tensei in full detail, we know from that there are some guys who know everything.
9) Due to 3, 4 and 8, Sasuke needs Tobirama.
10) Due to 2 and 7, Tobirama will get a place in the manga.

[~Supreme Itachi~]

you don't know a thing son

[★LssJBroly]

Possibly

[swapnil5843]

I don't think so he is the one but you did forgot one important thing about tobirama his one more Special Jutsu i.e Space time jutsu

[rikerslade]

Too bad he's sealed forever

[Melanee]

I think an Uchiha would make a lot more sense...

[Kages]

Maybe Lool

[JDuzumaki92]

I would think Hiruzen would be the "one". He was the hokage that was in charge when the massacre occurred . And he was the only one who wanted a peaceful solution. So Sasuke may want his input before deciding on revenge

[swapnil5843]

I would think Hiruzen would be the "one". He was the hokage that was in charge when the massacre occurred . And he was the only one who wanted a peaceful solution. So Sasuke may want his input before deciding on revenge

Coming this point in the series and considering Sasuke's personality and attitude I don't think he will listen or consider input from anyone but his parents. Which might have big impact on his decision about village and the clan.... Since he had heard Itachi part so it leave his father and mothers point of view IMO.....

[★Sir Derp Obito]

Sasuke asking about his clan from a Senju....... Awkward :D

[sacmador]

you don't know a thing son

Then inform us daddy

Too bad he's sealed forever

He needs Orochimaru exactly for this.

[The God]

its pretty obvious its his parents cos no1 knows where they were during the 9tails attack... Which is what caused suspicion on the uchiha even itachi didnt know where they were and he was lookin after sasuke

[lion fang master]

I doubt that the one is the second hokage. To me i thinks its madara brother, why ? Just because there always been 2 sides when it comes to the uchiha clan and from what now know that tobi is obito not madara, we cant believe anything that was said in the past from obito. So izuna to me makes sense he is the only 1 that knows what madara knows and i would bet he was against himbthat why hebtopk his eyes