Board Thread:Consensus Track/@comment-30913149-20170625232913/@comment-734582-20170626184542

The Wikia Editor wrote: It's why I suggested that transmigrants tend to be born within the Senju/Uzumaki and Uchiha clans. I don't think it matters what clan you're born into at all (not even Senju or Uchiha), just being transmigrants is enough.

if you think about it, what we know of Obito's trick, Edo Tensei, Biju, Hagoromo and transmigants actually matches quite nicely.

We know that information can be used to call back a spirit from the afterlife (ET). A body possessed by a spirit gains access to all that spirit's power (ET, Biju, Obito). Beings with the power of Rinne have the ability to be reborn, as long as some piece of that being still exists.

That last point is fairly easily proven: Madara could be brought back because some piece of him still existed (whether it was his body or his Edo tensei made by his body), Biju have their original Gedo mazo body, Hagoromo could be remade by Kurama Ashura and Indra, and Hagoromo's original power could be remade by just Ashura's and Indra's.

Both this reformation and reincarnation matches what we know from Biju: As long as someone sufficiently related to the transmigrants exist, the transmigrants can reincarnate because some part of them never left. The Biju cannot permanently die because their original body still exists. But also, the Juubi could be reformed simply by rejoining it's original chakra. Similarly Ashura's and Indra's chakra could be reformed into their father's simply by rejoining it in one body.

Obito could reincarnate (though temporarily, probably because he lacked the full power) because Kakashi still had some chakra after having his eye for literally decades. Kaguya could likely reincarnate because literally almost every being on the planet still has her chakra (IE you'd need to kill everyone to end her life, unlike Momoshiki/Kinshiki who have nobody left to carry some of their power).