Weird sarcophagus

This cell once held an unknown great man.
However, if you really count, this cell has been vacant for three years.
The terror that the great man once brought to the Imperial City gradually dissipated like smoke.
Fang Anzhi took a deep breath and looked at the bronze sarcophagus, feeling curious.
How could a simple sarcophagus be taken so seriously?
What exactly is imprisoned in here?
Just when the four extermination-level demon slayers carried the sarcophagus into the cell...