Enton Might As Well Be The Same As Amaterasu
I don't know where everyone is coming up with this idea that Enton flames and Amaterasu flames are different. The flames of both techniques are the same; it's just how they manifest that's different.
For example, Amaterasu is like Kakashi's kamui. It's a sniping technique. You focus on a distant object, and the black flames appear onto it.
Enton however, forms in a relatively close range and is it is NOT required for Amaterasu to be used before hand. Enton is of its own product.
The product, however, is the same; black flames that burn hotter than any flame for days, that cannot be extinguished. Enton and Amaterasu might as well be the same.