The momment kakashi eyes changed to MS is when his DNA in the eyes changed. There is no where that say susanoo requires only a pure uchiha chakra. Chakra that channel through changed DNA is almost same since the DNA that determine the inside body chakra.
You can not simple reverse it back.
You have your own idea like i have mine, but doesnt mean if you "think it is right" and apply it on other. You have to prove it by concrete fact which i have not seen it yet. Like when i tried to show you the DNA thing, because it is the best evident.
The eyes changed to MS that mean in order to have a MS, kakashi eyes must have enough of the requirement(DNA) like other Uchiha to achieve it.
If kakashi used susanoo only without DMS in that fight then your arguement is logic, but his eyes changed and awakened susanoo. And the concept of susanoo is the manifestion of chakra (no where in the manga state that it has to be 100% pure uchiha chakra even if it does some how, the concept of DNA applies). Kakashi met enough requirement to awaken his susano through his changed eyes - MS. The only thing left is how he is gonna pull out enough of chakra to perform PS. I think his best is ribs and hands, since he is not so young now.
No, his eye change because Obito chakra take over his body.
You still not answering my point on Ashura/Indra and Naruto/Sasuke.
Your logic is flaw because in NV, what is matter is chakra not DNA. Hashirama DNA can gave you Ashura chakra because he is transmigrant of Ashura. Same as Indra and Madara or Sasuke.
Obito chakra or Ashura and Indra chakra never altered their incarnations or host DNA, their incarnation or host DNA is still the same.
If you got half Hashirama cells body like Obito, here is where DNA comes into picture. Chakra will not do that.
DNA not determined chakra, my friend. Chakra and DNA are separated. You gained new power in NV is because chakra of the users is present inside his DNA. Itachi's MS in Sasuke's eyes, Izuna's MS inside Madara's eyes, Shisui's MS on Danzo is similar. Each of those eyes contained users chakra.
Kakashi not need any DNA changes but what he need is Obito chakra from Sharingan to assimilated with his own chakra. Inside Kakashi body or DNA contained Obito chakra.
Inside chakra, there was present all user powers.
DNA just carried Bloodline specialty like KKG( Sharingan, Bones etc), clan origin, abnormalities, parent behaviour, parent physical trait etc
As I said before Kakashi never got any physical transplant from Obito after Madara took his eye but spiritual transplant. Its clear that Obito himself is inside Kakashi's body not just an eyes.
Its like God gave you power and God take back all that power after that and what is left is just your normal self. Same as Obito and Kakashi case. The prinsipal is similar.
