Well technically the plan was Madara's and Obito was pretty much executing it, so you could argue that the true leader is Madara. And Obito had some serious setbacks, starting with Naruto getting Nagato (key to the plan) on his side. The original plan called for Nagato to sacrifice himself to revive Madara. I suspect that Obito modified that part to apply to himself, but Nagato killed himself for Naruto's sake, wrecking his plans - Obito's body is too damaged to become the juubi jinchuriki, but he could still perform Rinne Tensei, except he does not want to die for Madara. On top of that, Kabuto revived Madara with Edo Tensei, effectively denying him the option to use Rinne Tensei on him (or rather get someone else to do it
).
And he also messed up being too impatient and creating the Juubi before he captured the 8 and 9 tails. This will probably prove fatal to his plan.
In short, the true master was Madara, but the person who took over the plan (Obito) messed it up.
And he also messed up being too impatient and creating the Juubi before he captured the 8 and 9 tails. This will probably prove fatal to his plan.
In short, the true master was Madara, but the person who took over the plan (Obito) messed it up.