Darkness & Getting Stuck
Athan walked into another section before obliterating the wall and killing the final beast with two Chasm Severing. Of course, there was still one more wall left which required him another Chasm Severing.
He had to use eight Chasm Severings to kill the four beasts and destroy four walls, ultimately consuming 80% of his geno energy.
So in the end, It appeared impossible to finish it with just two people. If Ferexa was still alive, They could manage more appropriately from the start. Hemakel wouldn't have died since they could be more alert with additional pair of eyes and have each other's back.
Athan entered the door that appeared in the middle of the hall after he destroyed the last wall.
After going through that door, He appeared in a hall with five doors.
[ Pick one out of five doors. ]