Emery would have to decide which one he should choose between the three advanced skills available, but he was torn by it. If he could, he obviously wanted to learn them all. That was the problem and the reason he took a long time to contemplate his decision.
He give thought to the first advanced skill on the list, [Sword - Sonic Leap]
The three times speed boost was no joke, especially when one's speed was already monstrous to begin with. Taking the example of Emery, his 330 meter per second speed would jump to 1000 meter per second.
His speed would break through the limit and surpass the speed of sound itself. Furthermore, this sudden burst of speed would definitely catch his opponent off guard when used properly.
However, there were naturally some drawbacks about the skill that made Emery reconsider his choices.