Yun Jhin decided to settle in the city for some time, now that he had the devil organization under him he could use the natural pool under their jurisdiction which was also recoverable.
Yun Jhin's new human body didn't attract much attention as he was exuding a devilish charm that showed that he was an inhabitant of Hell, from absorbing so much demonic energy he was basically just like the average devil in regards to presence.
The location of the other demonic pool was nearby the city, after all, they constructed the city around the pool's location to make sure no one would use it besides the people they wanted to.
Unfortunately, the pool had been used a few times due to the former war so it was quite depleted, also recovering it took a lot of time so Yun Jhin could only use around 50% of its energy, it wouldn't be enough for him to reach the second stage of the sage realm as it wouldn't strengthen his avatar enough.