It is clear that the strength of that immortal is not to be underestimated.
Old Man Yang continued, "However, based on my observation and analysis, the immortal seems to still be cultivating some kind of special formation. Every once in a while, powerful energy fluctuations erupt from here—tremendously strong, capable of shaking the entire prison."
"Judging by those energy fluctuations, they are not natural. Otherwise, they wouldn't be so regular. But as for what specific formation it is, I don't know yet."
Chapter 1028