How can Madara still stick around even after the Edo Tensei had been ended?


Edo Tensei is a technique to revive the dead, and bind their souls into living
bodies. However, after releasing the technique, all of the dead should get
back into being dead.

How can Madara still stick around even after the Edo Tensei had been ended? I
am not sure if it was something that we needed to think about and figure out
by ourselves or is it yet to be revealed?




Firstly, the most important thing to know is that anyone, who knows the Edo
Tensei seals, can free themselves from the contract, if given the opportunity.
Now, there are multiple ways that one can be unrestricted in Edo Tensei form.
These are their opportunities:

  1. The grace period when one's soul is released (Example: Dan meeting Tsunade)
  2. The revived person is strong enough to withstand the Edo Tensei (Example: Hashirama not under Orochimaru's control)
  3. The controller allows the revived person free movement (Example: Madara being revived by Kabuto)
  4. Some other force is able to place a stronger control over the revived person (Example: Kotoamatsukami being used on Itachi)

In Madara's case, Kabuto had claimed to revive him in a form stronger than his
prime. Madara questions Kabuto's ignorance of his prime state and then Kabuto
gives Madara full control of his own body in order to demonstrate his
abilities.

**After Kabuto gave control to Madara, Madara was able to use the Edo Tensei
seals to free himself.**

![enter image description here](https://i.stack.imgur.com/pbYHE.jpg)




When Edo Tensei ends, the summoned soul is freed from the Edo Tensei's
control, and then the soul ascends to the pure world (afterlife). However,
there is a small "grace period" between the two. During this grace period, the
soul can act freely.

> During that grace period, Dan used the Reika no Jutsu to go meet his
> girlfriend. Itachi shared his memories and feeling with Sasuke (though
> granted he had been freed from the Edo Tensei's control long back). Most
> other shinobi stood around doing nothing significant.  
>  However, during that grace period, Madara released the Edo Tensei's
> summoning contract itself. As such, his soul is no longer bound to "ascend
> to the pure world" and can continue to stay in the impure world.

He could have done the same thing even before the Edo Tensei was released, if
Kabuto had let him, and the effect would be the same. Also, if others knew the
seals and chose to use them, they would be able to stick around too.

