More importantly, to open the hidden entrance on every floor, one had to collect ten keys altogether. These ten keys could be found in this hands of several Castellans of the Kingdom of Devils. The problem was, this Kingdom of Devils had at least ten thousand cities, if not a hundred thousand.

Therefore, Huang Xiaolong had to first determine which Castellan held a key and move to snatch it.

A dark glow cocooned Huang Xiaolong’s body, altering his face and physical appearance. In a few short moments, he looked exactly like a devil, whistling through the air as he flew towards the closest city.

A short while later, he stood in front of a devil city’s gates.

This city’s walls were actually built out of a rare material from hell called Underworld Marvel Stone. Those rare stones were piled high over each other, glistening and emitting devil qi.

Stepping into the...