Yeah I know this is a long shot but still I couldn't resist.
So we know for a fact that in narutoverse there is a god who grants you immortality and in return he asks you to kill people as sacrifices. We also know that a religion was created to worship him and that the only known member of it is Hidan ( I don't say that Hidan is an uzumaki!).
However, a religion, no matter how small it is, it needs many people to be created and I just don't think that Kishi just threw this Jashin guy for no reason.
As we know, Hagoromo had a brother, who sealed the Juubi along with Hagoromo inside of the latter. Nothing else is known for him. However, the sealing abilities creates the chance of him being the ancestor of the uzumaki (he might also be of hyuuga but it's not really important about what I'm going talk about).
Seeing his brother's power could have made him jealous and we have seen how jealousy has affected many characters throughough the history of naruto. Therefore, if his brother created ninshuu, it would make sense for him to create ninjutsu since that brings wars and Jashin's rituals require sacrifices.
As for the uzumaki clan we know that it was fearful but we don't know the exact reason, presumably it was because of their sealings. We also know that it was a clan of priests.
Here comes the interesting part: What if the this clan of priests was devided into 2 sides: the ones who seek peace and the ones who seek power and desire to conquer the world? Same as ninshuu and ninjutsu.
I would like to point this out: sealing abilities -at least the uzumaki ones which were used till now- are for defensive purposes. Ofc, you can say that from them it came the method of becoming jin which gives you power but at the end of the day, it's a method to seal a dangerous beast and the same goes for Death reaper seal.
That last seal is obviously Kaguya which strengthens my opininon about Hagoromo's brother's relationship to the uzumaki.
What am I trying to say is that a clan that it's only known for their defensive abilities can't really be considered dangerous since that would mean that they don't have offensive power, especially if they wanted peace.
But if Jashin was hagoromo's brother, then imagine a whole village of immortal people, working together while they also have these sealing abilities. Now, I don't say that every uzumaki is a jashinist but that there was indeed a war between of them, between the ones who wanted to live peacefully and the others who wanted power.
An immortal village, surely, no matter how small it is, it would pose a great threat. So you could say that half the village believed in ninshuu while the other half in ninjutsu.
I would like you to consider for a second the death reaper god sealing. The specific one takes away one's soul along with its user. Thus it would work on an immortal guy because immortal or not, soul is a complete differen subject. Therefore, that technique might have been used to stop the Jashinists by sealing them away.
Returning now to the religion's matter. For a religion to grow, it must spreed and to spreed in needs people, a lot of them, surely there would be many people like Hidan who would desire power and thus if this religion was to spreed it would put the whole world in danger. To stop the growth of a religion, you must stop its source, nullifying it in fact. Do you remember what happened to the uzumaki? Total annihilation. The other villages might have used uzumaki's sealing to seal away the Jashinists and later they might have killed the whole clan, whatever their religion was, to make sure that they wouldn't pose any threat in the future.
I mean look at Hidan for example: this dude is a complete idiot, without any special fighting abilities and yet he reached akatsuki's level power only by being immortal. Imagine how this immortality would work on a genius.
I hope that you liked my theory =D It's a bit far-fetched indeed but just imagine what a huge twist would be if the clan that was always depicted, as a clan of angels, was the stronest in the history and despite its history for being priests, were in fact the source of a satanic cult as dangerous as the Jashinist one!
So we know for a fact that in narutoverse there is a god who grants you immortality and in return he asks you to kill people as sacrifices. We also know that a religion was created to worship him and that the only known member of it is Hidan ( I don't say that Hidan is an uzumaki!).
However, a religion, no matter how small it is, it needs many people to be created and I just don't think that Kishi just threw this Jashin guy for no reason.
As we know, Hagoromo had a brother, who sealed the Juubi along with Hagoromo inside of the latter. Nothing else is known for him. However, the sealing abilities creates the chance of him being the ancestor of the uzumaki (he might also be of hyuuga but it's not really important about what I'm going talk about).
Seeing his brother's power could have made him jealous and we have seen how jealousy has affected many characters throughough the history of naruto. Therefore, if his brother created ninshuu, it would make sense for him to create ninjutsu since that brings wars and Jashin's rituals require sacrifices.
As for the uzumaki clan we know that it was fearful but we don't know the exact reason, presumably it was because of their sealings. We also know that it was a clan of priests.
Here comes the interesting part: What if the this clan of priests was devided into 2 sides: the ones who seek peace and the ones who seek power and desire to conquer the world? Same as ninshuu and ninjutsu.
I would like to point this out: sealing abilities -at least the uzumaki ones which were used till now- are for defensive purposes. Ofc, you can say that from them it came the method of becoming jin which gives you power but at the end of the day, it's a method to seal a dangerous beast and the same goes for Death reaper seal.
That last seal is obviously Kaguya which strengthens my opininon about Hagoromo's brother's relationship to the uzumaki.
What am I trying to say is that a clan that it's only known for their defensive abilities can't really be considered dangerous since that would mean that they don't have offensive power, especially if they wanted peace.
But if Jashin was hagoromo's brother, then imagine a whole village of immortal people, working together while they also have these sealing abilities. Now, I don't say that every uzumaki is a jashinist but that there was indeed a war between of them, between the ones who wanted to live peacefully and the others who wanted power.
An immortal village, surely, no matter how small it is, it would pose a great threat. So you could say that half the village believed in ninshuu while the other half in ninjutsu.
I would like you to consider for a second the death reaper god sealing. The specific one takes away one's soul along with its user. Thus it would work on an immortal guy because immortal or not, soul is a complete differen subject. Therefore, that technique might have been used to stop the Jashinists by sealing them away.
Returning now to the religion's matter. For a religion to grow, it must spreed and to spreed in needs people, a lot of them, surely there would be many people like Hidan who would desire power and thus if this religion was to spreed it would put the whole world in danger. To stop the growth of a religion, you must stop its source, nullifying it in fact. Do you remember what happened to the uzumaki? Total annihilation. The other villages might have used uzumaki's sealing to seal away the Jashinists and later they might have killed the whole clan, whatever their religion was, to make sure that they wouldn't pose any threat in the future.
I mean look at Hidan for example: this dude is a complete idiot, without any special fighting abilities and yet he reached akatsuki's level power only by being immortal. Imagine how this immortality would work on a genius.
I hope that you liked my theory =D It's a bit far-fetched indeed but just imagine what a huge twist would be if the clan that was always depicted, as a clan of angels, was the stronest in the history and despite its history for being priests, were in fact the source of a satanic cult as dangerous as the Jashinist one!