...What else of Orochimaru's stuff will be stolen and him not noticing until the lack of it becomes very relevant and inconvenient for him?
Sadly, Orochimaru is very much like a vermin infestation: No matter how many setbacks he suffers, as long as he's not
completely gone he'll inevitably return even more troublesome than before.
A lot of people were super upset about how Orochimaru got 'redeemed' in canon, but IMO that was the only realistic option: The man is fucking
impossible to kill. Convincing him that his quest to learn all the jutsu was inherently impossible (because new jutsu and bloodlines are constantly being created) and that he should stop being an asshole just for the hell of it, declare a truce and at least
try to keep his experiments
vaguely ethical (by ninja standards) was really the best possible outcome.
And to be entirely fair; after calming the fuck down and switching to using cloned bodies for his immortality technique, Orochimaru proved to be
extremely useful to Konoha. Dude
is a legit genius at SCIENCE! after all.
He just needed to get his shit kicked in a few times and then get exposed to Naruto in maximum Friendship Mode.
We have nine tailed beasts, and Indra and Asura reincarnating themselves. Thats 11 connections to the reincarnation net. Who is the 12th? Is it the Sage, Is it 10 tails?
Kaguya\Ten-Tails I would assume.
e: Could also be Black Zetsu; him having access to the Ōtsutsuki's reincarnation net would make sense, as he is a 'piece' of Kaguya, probably not unlike how the Tailed Beasts are 'pieces' of the Ten Tails.
Actually Black Zetsu being sort of a knockoff Tailed Beast made out of Kaguya's Chakra, instead of the Ten-Tails' Chakra, would explain a
lot about him.
e2: Could also be something to do with the Moon Clan Ōtsutsuki, who I think are down to just Toneri and his puppets at this point in the timeline. Toneri himself never showed any Ōtsutsuki reincarnation stuff, but they
did have that Energy Vessel Tenseigan full of eyeballs, which Hamura had supposedly created way back when. So
that might have some kind of connection to the Ōtsutsuki reincarnation net.
e3: Also also could be Orochimaru. No fucking clue
how he'd have gotten access to it, but if there's
anyone who could figure out how to connect to a magical reincarnation network entirely on their own without even knowing said network exists in the first place, it
would be Orochimaru.
Personally my bet is on Kaguya\Ten Tails\Black Zetsu though: It makes too much sense, especially since we know the Tailed Beasts were connected to it and they were created out of the merged Kaguya + Ten Tails.
That's not "incompetent", that's "someone did something that shouldn't have been possible without blowing up a star and we have to scramble now to avoid being completely wiped out as a side effect, write off that sector forever and stay the heck away!"
Yeah, it's really nice to see the Ōtsutsuki take one look at the Outside Context Problem that is fucking up their shit, go 'nope' and just cut their losses instead of taking unnecessary risks.
Because that is
exactly what you would expect a literally interdimensional and interstellar (possibly even intergalactic) faction that is harvesting an unknown but probably considerable number of planets throughout the multiverse to do; the loss of a single planet just isn't that big of a deal when your faction is harvesting potentially dozens of planets at any one time, and said harvesting process takes ages to finish
anyway.
(We get a brief shot of the world that Momoshiki had recently finished harvesting and it is
covered in God Trees, hundreds of not thousands of the things. Given that it takes a fully grown God Tree 1000 years to produce a Chakra Fruit, the process of planting
that many God Trees must logically take hundreds of thousands of years at
minimum. Which makes sense: Planets are big yo.)
There is absolutely no good reason for the Ōtsutsuki to take that risk; nothing they have lost from this is not completely and entirely replaceable, and they are
already over-extending themselves.
No, Shihiki's response was extremely sensible and unusually competent by Anime-villain standards.