I don't know if anyone thought of this or if this was already mentioned but I think I know why Spiral Zetsu crumbled after IT was broken, its because the one that was cast by Kaguya originally to create him and various other zetsus was never broken and IT is the thing that keeps the Zetsus alive.
IT turns people into White Zetsus even though it should kill them, so my theory is that the jutsu also keeps them alive and that once it is broken all the zetsus created by it die as well.
The Sage said he researched how to break the IT but from his speech it sounds like it was never tested and since the moon wasn't around during the time of Kaguya, she must have cast IT on groups of people rather than the entire world at once, and after sealing her the Sage didn't know how to deal with the White Zetsu so he sealed them inside the moon along with Gedo Mazo.
When Naruto and Sasuke broke IT that Madara cast they broke the IT that Kaguya cast to create all those White Zetsus, so all the white Zetsus died when it broke.
What do you think of my theory?
IT turns people into White Zetsus even though it should kill them, so my theory is that the jutsu also keeps them alive and that once it is broken all the zetsus created by it die as well.
The Sage said he researched how to break the IT but from his speech it sounds like it was never tested and since the moon wasn't around during the time of Kaguya, she must have cast IT on groups of people rather than the entire world at once, and after sealing her the Sage didn't know how to deal with the White Zetsu so he sealed them inside the moon along with Gedo Mazo.
When Naruto and Sasuke broke IT that Madara cast they broke the IT that Kaguya cast to create all those White Zetsus, so all the white Zetsus died when it broke.
What do you think of my theory?
i was mad he died without doing anything.