Vertical Slash. For any class wielding a sword, like a blader or swordsman, it was a skill they would learn right as they reached level one. However, Aster just learned it at level four. This wasn't an error but was the natural course, as he lacked the prerequisites to learn it.
First, he didn't have enough strength. Of course, this wasn't pertaining to the STR stat but rather to overall strength. When he was under level 3, his overall power was below the minimum prerequisite for learning the skill.
Second, Aster was unlike others who "earned" jobs through training and earning a skill. Technically, he was still "jobless" and was someone who simply was swinging a sword and gun around. As such, without a Job's Status Correction, it was obvious he would learn the skill slower than the others!
'But a skill is a skill! And it's amazing!'
