Why did Tobi wait until Itachi died before he revealed himself as Madara?


When it comes to manipulation, deceit, and lies, everyone pales in comparison
to Obito Uchiha and Madara Uchiha who devised the whole Akatsuki plan (well,
maybe, except Zetsu). Madara offered Obito his identity. Obito walked the
earth as Madara but most knew him as Tobi.

When Itachi Uchiha died, as soon as Zetsu announced that Itachi is no more,
Tobi for the first time revealed his Madara voice and let Kakashi and the Leaf
Shinobi see his Sharingan.

The part I never quite grasped about the Tobi persona setup was:

1- Obito patiently waited so many years and kept presenting himself as Tobi
(except to Pain, Itachi and some others), so what is the reason which made him
decide the time has come to blow up his persona?

2- What has he been waiting for before revealing himself? Is the death of
Itachi somehow a factor for his revelation?

3- What big impact did the Tobi persona bring to Obito, why not
straightforward present himself as Madara? The reason he played Tobi did not
bring much as far as I can think.

Also, at the start of Shippuden, when Sasori died and Tobi and Zetsu scavenged
the remains of the battle, why Obito had to keep up his persona Tobi in the
mere presence of Zetsu who not only knew he pretended to be Madara, but also
knew him as Obito?

Please enlighten me.




Update: Late in the episode: _Episode 455: Itachi's Story--Light and Darkness:
Moonlit Night_ , Obito says something to Itachi that supports what I wrote
below. It's basically an answer to this question in his own words.

> **Tobi:** Within the organization, I'm known as Tobi. I'm not an official
> member. I'm a newbie within the Akatsuki who doesn't possess any spectacular
> jutsu. You should treat me as if that's true.
>
> **Itachi:** Why hide your identity?
>
> **Tobi:** If people knew Madara Uchiha was still alive, things would become
> complicated. Only the Akatsuki leader who we're meeting knows the truth.

The Tobi persona was actually very useful for keeping the heat off of him.
Let's not forget that for most of the series, Pain was the acting leader of
the Akatsuki. Obito was in the shadows, pulling Pain's strings. We can see
this pay off, because he manages to avoid Jiraiya investigating him (he
investigates Pain instead). And since he would rarely be around the Akatsuki,
Obito was likely able to frustrate Itachi's efforts into looking into him
(given Itachi never seems to have discerned he wasn't actually Madara). Itachi
and Jiraiya are two people you definitely want to avoid sussing out your
secrets, so I'd say staying in the shadows for so long was a really smart
move.

I'll note, as said in another answer, Itachi was aware Tobi was Madara Uchiha.
The Itachi light novels show him intuit this. Itachi actually comes
dangerously close to guessing Tobi might be an Uchiha who went missing during
the war (the truth), but in the end decides he must be Madara Uchiha. (see my
answer here for quotes: <https://anime.stackexchange.com/a/66266/19307>)

Even after joining the Akatsuki as Tobi, Obito flies under everyone's radar
because he acts like a total moron. Thus, he's still kept out of scrutiny and
danger, as most people would rather try to investigate the leader Pain. But at
the same time, the Tobi persona gives him the ability to monitor Akatsuki
operations and members up close (such as Deidara).

Let us also remember what happens when Tobi reveals himself as Madara Uchiha
to the kage. He's perceived as enough of a threat that the five great nations
join together to try and crush him. That's how powerful the name Madara Uchiha
is. If he'd revealed that too soon, before he was ready, all the Biju may have
forever slipped out of his grasp. Obito has to carefully plan when and where
to play this dangerous card, and he only goes public with it when he's reached
his endgame. This isn't to say he never used this card before then; he
revealed himself as Madara Uchiha to several individuals.

