C3431 Invincible Little Black

Guu Feng was puzzled when he saw Xiaohei No.1 and those silver devil heads trapped in a transparent crystal dome.

"What is he trying to do?"

"This is a strength experiment." Purple Copper pointed at the crystal barrier in the center of the field and explained:

"Xiaohei No.1 is the strongest among all the devil chiefs. It can easily penetrate ordinary rooms.

Therefore