Although Yale continued training his disciples and improving the Essence Slayer Sword for the next two months, his mood was quite gloomy when he was alone.
Yale had yet to create a method to reach ninth level immortal, and the one he obtained from the criminal he killed wasn't suitable for him, so he was struck out at eighth level immortal without being able to improve even a bit.
The only way to advance would be skipping the level due to external factors like when he advanced to seventh level immortal without wanting to do it, but he knew very well that it was an exceptional case and the chances of something like that happening again were almost inexistent.
Moreover, he had been at the peak of the sixth level immortal at that time, while he hadn't advanced a bit after becoming an eighth level immortal, which made it even more difficult.
