Sky Changing Pass

Ace was moving at lightning-like speed, but his movement was a little rumpled as if he was learning to run. 

This was the Misperception Sky Steps Art, Lightning Steps. 

This art is not like the heartless stealth that can only be learned in a strict order.

This art is built on three unique movement patterns, and only after learning these three stages, complete one can gain the ability to fly and learn the final fourth stage.

It means Ace can learn three stages at the same time or understand any stage first before learning the others. 

That's why he chose the lightning steps first, because this is for speed, and he only needs speed right now. With silent steps as the foundation in four days, he was very close to low-level, lightning steps.