I think Amaterasu is one of those huge fireball techniques that the Uchiha clan was so good at. Im guessing it looks like the regular fireball just black flames and a hell of alot more powerful. Just a theory tho
If the third move is a taijutsu move though, does it still require the Mayo-whatever-sharingan?(im assuming it does because the other 2 do) And If so what part do you think it plays in the actual execution of the technique?