It was said in the databooks but....
Here Itachi states that Susano'o awoke with Amaterasu and Tsukuyomi.
You must be registered for see links
Then here, Sasuke says that only those who have the double (two) Mangekyo can use that power.
You must be registered for see links
The manga pages don't EXPLICITLY state that you need those two powers, but seeing as two of the three users of Susano'o have Amaterasu and Tsukuyomi usage, we can conclude that those are the two powers you need to use in correlation to use Susano'o.
We also cannot say that all Mangekyo activate the same jutsu seeing as Kakashi has Kamui and Shisui had Kotoamatsukami.
66% chance of that being the case until we see Madara using any other Sharingan techniques.