The Sun Chasing Sword Art was a lower sky breaker sword art, which was split into seven sword styles. Each sword style for each cultivation realm from 1st to 7th.
Each sword style was then further split into three profound sword moves, and all 21 moves combined were called the true Sun Chasing Sword Art.
Ace, at this movement, was in the Sword Stealing Time state, and he activated it after remembering the entire book. Now, he was grasping the true essence of the 21 moves. Furthermore, he was in this state for over twenty minutes, which also proved his theory that the higher the skill he memorized, the more sword-stealing time he would get.
However, this was also a fact that the higher the skill he wanted to grasp, the more time he needed in this state. Just like right now, he was still only in the process of comprehending the 13th move, and he was nowhere done, and he had no idea when the time would end.