After spending some time learning about Arts, Axel successfully added two to his arsenal:
*Unholy Art: Shattered Earth - Summons forth several large spikes in a predesignated area.
*Unholy Art: Shadow Strike - Releases a black fog in the immediate area that only the user of the Art can see through. Remains until the user dispels it.
Shattered Earth was definitely something he had already mastered, but Shadow Strike could be a hit or miss sometimes. Due to the additional parts of the Art(being able to see through it and being able to control how long it lasts), it added another layer of complexity to it. But Axel could pull it off most of the time, so that was good enough.
As Axel and Iris continued their journey, they were still out of leads as to where Tetia could be holed up. So they decided to just keep pushing forward and gaining as much experience as they could.