How Madara gained rinnegan

[Rigswattwa]

The most probable reason why madara have gained the rinnegan in his last moments is this

We all know that the rinnegan means the power of the Sage of Six paths but sage had two son as we know Uchiha and Senju .......
What i mean to say that in a way the sosp that both the power of uchiha and the will of fire of senju Thus Madara must have gained the Will of fire and ems and got the rinnegan

 

[Bruce Banner]

Madara buy the Rinnegan from eBay 50% discount.

 

[Gatsuuga]

Madara buy the Rinnegan from eBay 50% discount.

haha.... but latter found out he was beaten by tonton who used the "buy it now" option. Such a crafty pig.