What could be Madara's final triumph card?, has it something to do with obito?
As we saw with the right translation, Madara wants to get more of Hashirama's cells.
And with the recent revelation of senjutsu actually working on Obito, im quite convinced that what Madara is trying to achieve Hashirama's sage mode.
The thousand hands mokuton jutsu that Hashirama used against Madara could perhaps be of great danger to Obito due to its senjutsu nature.... After all, it did not only deal with the kyuubi but also with Madara's Perfect Susano...
Obito is rediculously powerful but hes not invincible