On the fifth floor, the group encountered a horde of A-rank dark creatures. They got sneak attacked at least fifty times every day. B-rank dark creatures became fewer and fewer just as Fein expected. From their entire exploration on the fifth floor, they only killed ten B ranks.
The dark creatures mostly blend in the darkness and attack when their target were occupied by something.
They are characterized by their vicious approach. For Fein, the dark monsters were sneaky rat bastards. If not for Fein's perception, they might not have passed the fifth floor unscathed.
The danger of the fifth floor doesn't depend heavily on the strength of the dark creatures. But by their means of attacks.
Fein and others rested nine times on the fifth floor before they reached the space teleportation circle.
