A dense gathering of mana
The Wanderer class bat was charred by Almina's Flame Wave.
Yman felt all the bone in his body was crushed by Almina when it crashed onto him. He had to use his healing ability multiple times.
Although Almina said her sorry to him and to Mercenary Ultima, he told her that she didn't have to, in the first place it was his plan.
Since the enemy was charred and most of its flesh and bones were wasted, they could only take the Inner Core and Magic Cryst from it. Well, it was the most valuable part of this monster.
Yman and the rest had lingering doubts about the place. The farther they advanced, the more they found out that this underground wasn't ordinary.
As they go deeper, space inside becomes wider and wider.
Not only that, but there were multiple alleyways also. They even noticed some kind of crystalline objects stuck on the walls and ceiling. It radiated the place with cobalt radiance.