Uzumaki+Senju+Uchiha= Rinnegan

Theory:

Spoiler:

Nagato is a Uzumaki & Senju Lineage (Nagato — a young Senju descendant) child but why did madara pick him because his bloodline and if jirayia did known nagato was the next sage why wasnt he really shock??? he must have known he was a uzumaki by the hair like but tsunade grandma and her grandfather (who was Senju+Uzumaki) nagato showed "Uzumaki blood" more then both naruto and tsunade making nagato a true 2nd sage because of the fact the sage is a uzumaki

Quote :

re-merging his bloodlines: that of the Senju and Uchiha can lead to that person awakening the dōjutsu. This was proven when Madara later awakened the dōjutsu by infusing Hashirama Senju's DNA into his body; however it did not manifest until he was near the end of his natural lifespan.

from my statement above when it was manifested in nagato his rinnegan was quickly awaken from the pain of his parents deaths.....while for madara a near death and nagato wasnt near any death experiance




Madara Uchihas Mutation:

Spoiler:

Madaras mutation was very strange on how nagato was also given uchiha blood from the transplants but has never have shown or said to mutate and just like danzo he did it differently danzo "injected" while hashirama blood was in madara wound causing a blood fusion and this gained them both abilities of the wood release and a face of hashirama but why not nagato? for this i answered because uzumaki blood cant be mutated

Gedo Mazou:

Spoiler:

After noticing why the gedo had put chakra rodes in nagato was because he was confused because one moment he was controlled by madara and then nagato and so putting in the rodes and taking chakra had comfirmed his new controller

Rinnegan Users abiltities:
Madara only used preta path (shattered heaven isnt a real rinnegan tech more of a combined tech)
Obito only showed using the six paths of pain tech
Nagato had showed more progress then both of using all paths and a new rinnegan tech and stated by jirayia nagato easily had mastered all 5 natural ninjustus

Why?? Madara had years to master the rinnegan (a near +25 years) but he didnt even try meaning he didnt know how to until he was edo and so did obito showing no real rinnegan tech and nagato at a young age was already Kage level and ten later god status

Conclusion:
Thanks to studying the manga carefully the sage's clan and somewhat history and finding how to obtain the rinnegan is or might be a 3 way step.....
1. Senju+uchiha Dna
2. Near Death....or Pain?
3. Uzumaki DNA

Why?? Uzumaki have strong body's & extreme chakra reserve.......Senju have great physical abilities & spiritual energy.........Uchihas have the "Dojustu" & powerful chakra

rinnegan users arent dont know how to use the rinnegan right away but is a slow progress......if your a uchiha but for a uzumaki to show more progress then 2 dojustu users that had them for years