Because of failure, that civilization no longer had a reason to continue cultivating Death Soldiers, and this place was gradually neglected, ultimately being completely sealed off.
Perhaps, some bored individual painted everything that happened into murals and recorded them in these ruins, hoping that one day, subsequent civilizations could glimpse the tip of their civilization's iceberg and not let their legacy be forgotten by the long river of history.
The black energy wandering within the ruins was the tool this civilization used for testing humans.
In the ruins, there was something that caught the eye, which was like a congregation of black energy similar to Slime.
According to Yang Yu's conjecture, the special AI—black energy—created by that civilization may have undergone some transformation over the long years, with some even developing their own consciousness, shifting from aimless, floating black energy into a physical "creature."
