Huh, so maybe Jashin could be one of the unaccounted for reincarnation node things. It's just using it in a completely different way.
Unlikely, Jashin's unkillability ritual works completely differently from the Ōtsutsuki reincarnation.
No I'm more inclined to believe that Jashin is exactly what Hidan says he is; an evil god of death and destruction who is willing to offer his followers a ritual to become unkillable in exchange for human sacrifices.
Considering all the crazy shit that is known to exist in the Naruto world, including multiple different types of demons that are unrelated to the Ten-Tails, spiritual entities of death that can eat souls to prevent them from passing on to the Pure Land, glowing rocks (that are almost certainly from a meteorite impact, given what the 'vein of Gelel' looks like) containing nigh-unlimited life-force energy, and who knows what else, I don't find it hard to believe that the setting also includes an evil god of death and destruction who calls himself Evil God.
Which leaves one unaccounted for, which is most likely Kaguya's former partner that she betrayed. He's still alive and one of the main baddies in Boruto.
It shouldn't be Isshiki; as a 'proper' Ōtsutsuki he's using the Kama and thus would have a normal Kama node connection to the network.
Which, incidentally, just got cut off. So depending on what exactly Isshiki is up to (it's unclear when exactly in the timeline he formed Kara, but given the ages of the people involved it
probably happened after the events of Shippuden), he's going to be having a bit of a panic attack as his Kama gets disconnected.
Whether or not this will be fatal to him is unclear, given that he isn't actually
using the Kama to puppet Jigen's body, and even if he has founded Kara he definitely hasn't found Kawaki yet. So he should only have the Kama on Jigen which he can't actually use to reincarnate, due to Jigen being incompatible, and is instead just having it slowly overwrite Jigen's DNA with Ōtsutsuki DNA so as to make him a better sacrifice for the Ten-Tails seedling (that he somehow acquires) in the future.
And without the Kama, Isshiki's plans to grow a new God Tree and get things back in track have gone up in smoke. So if he does survive being cut off from the network (and I see no reason why he wouldn't, given that he survived by parasitizing Jigen because he
couldn't use the Kama at that point) I would expect to see a hysterical Isshiki\Jigen show up at some point.
Isshiki is
not going to be a happy Ōtsutsuki, though it'll be interesting to see if he realizes what actually happened (the rest of the clan deemed him a lost cause and cut their losses) or if he blames something else for his latest round of dire misfortune.
(Seriously,
nothing has gone right for Isshiki ever since he arrived on this world with Kaguya.)
e:
And probably a decent amount of unknown others and not strictly just their descendants
Nope, Indra and Asura's reincarnations were
explicitly into their descendants; the Uchiha and Senju respectively. Madara and Hashirama were also explicitly the previous reincarnations before Sasuke and Naruto, though we don't know how many times they reincarnated prior to Madara and Hashirama. (It is mentioned that they reincarnated 'for a millennium after their deaths', so depending on how much down-time their is between reincarnations they could have had up to a dozen or so before Madara and Hashirama.)
e2:
Oh, actually. Now that I think about it; the 'missing' connections in the Ōtsutsuki network
might be the other Demons like
Mōryō and the
Zero-Tails. We don't actually get any information regarding the origins of those guys, other than that the Zero-Tails was 'created by the dark thoughts and feelings of the downtrodden' somehow.
There's also
Satori and the
Box of Ultimate Bliss, and according to Gamabunta the BoUB has been around since the time of the Sage of the Six Paths, so it and Satori being one or two (it's unclear whether Satori is actually an entity that the BoUB creates and controls, or is just like the BoUB's limbs) of the abnormal connections matches up timeline-wise.
Actually, I think that might be it: 9 Tailed Beasts, 1 Asura, 1 Indra, 1 Mōryō, 1 Zero-Tails and 1 Box of Ultimate Bliss\Satori. That's 14, which is the number of abnormal connections.
The numbers add up, and Mōryō, the Zero-Tails and the Box of Ultimate Bliss all potentially date back to around the Sage of the Six Path's era, which matches CmptrWz's timeline for the abnormal connections.
e3:
Alternately, the
Three-Headed Guardian Beast is another possible candidate, as it was said to be a living mass of Chakra much like the Tailed-Beasts. So if I'm wrong about Mōryō, the Zero-Tails or the BoUB, it might be one of the connections instead.
Probably not
Rōen or the
Genryū though; Rōen was a normal (albeit incredibly large and powerful) animal and the Genryū are just straight up dragons.
