I assumed that him coming in to contact with Rikudou chakra is what allowed him to recognize and use senjutsu the way he does. It's not SM level but it's something. Not to mention that he is an ex CM user. He used to handle senjutsu without even knowing it. With Naruto amassing so much natural energy, it didn't seem like a surprise to me that Sasuke could feel it.
I'm speaking about the current context. As far as manga has told, Sasuke now is able to see through Limbo, and feel Senjutsu chakra to some extent. But we don't know for sure if his black chidori is Senjutsu per se. So the whole thing about Rikudou giving him senjutsu capabilities is conjecture. So I'll thank you if we leave these theories for other thread. Let's speak about the current one.
I assumed that him coming in to contact with Rikudou chakra is what allowed him to recognize and use senjutsu the way he does. It's not SM level but it's something. Not to mention that he is an ex CM user. He used to handle senjutsu without even knowing it. With Naruto amassing so much natural energy, it didn't seem like a surprise to me that Sasuke could feel it.
All we know is that Sasuke can use Senjutsu moves if he possesses kneaded senjutsu chakra, which used to be the role of the Curse Mark. This said, he has the expertice to use Senjutsu if he has the Senjutsu chakra given to him (just like Juugo did in the Senjutsu Susano'o). Chakra doesn't come magically from nowhere, he needs nature energy to create Senjutsu chakra.
...but there is another way for this purpose: The Juubi. When the beasts are merged, the Juubi emerges, and SM Naruto already told as fact that Juubi is pure Senjutsu Chakra. The Gedou Mazou was just a shell to contain the chakra of these beasts.
Kurama stated in the last chapter that Sasuke managed to start merging the beasts within his Susano'o. Why would it be strange to assume that the merged chakra is in fact, Juubi's Chakra? (Senjutsu chakra)
No the sages chakra he gave to Sasuke is senjutsu. Thats why Sasuke's able to use the black chidori.
^ What he said.
Sasuke is using the bijuu's chakra as a vessel for his susanoo to force naruto to go all out, nothing more.
That's not the topic in this thread, mister. Also, I won't accept your conjecture of Rikudou's Chakra = Senjutsu Chakra, you don't hold proof of that claim.
The two ways to create Senjutsu chakra is: Juubi, or Nature Energy + Physical Energy + Spiritual Energy. Prove that, in other thread.
So I'll gladly thank you if you stay on topic.