Thorough

When the echo of the thunderous roar had finally subsided, Nial and the cadets were finally able to breathe properly once again.

Neither of them were aware of the fact that their breaths had caught in their throat and looked at each other in fear.

Meanwhile, Nial continued to release his mana currents, and felt oddly calm after the short moment of shock was over.

'There are definitely beasts that are stronger than petrification rats in this dungeon….' He thought, but that was quite obvious.

In the end, there had to be at least one boss, and there could also be rare bosses and other types of beasts than the petrification rat lurking in the dark.

As such, the dangers of the dungeon were not surprising to him.

Nevertheless, the thunderous roar was not even amplified by mana or initiated by the utilization of an ability, yet, it shook him and the cadets to the core.

This meant that they were innately weaker than the beast that had just let out a booming roar.