Amy and Miles were walking around the Hidden Library while checking out different Domination Arts one by one, seeing if any one of them were to their liking and if they could perhaps learn them.
However, just like Nash, even though they had been walking around the eternal-like place for almost 10 hours straight while also checking and reading hundreds if not thousands of scrolls and books, they too were only able to learn 1 True Domination Class Art.
The Domination Art that Miles was able to learn was called Motion Separation at the Lesser Grade. Though, despite being the weakest form among True Domination Art, Motion Separation was a Domination Art that perfectly aided his Thousand Esoteric Marks in various ways!