C515 Torrent

Chen Feng is about to summon the dragon, the expected roar, however, it had completely disappeared. Chen Feng used his hearing to probe. However, he found nothing. After a while, Chen Feng relaxed and let Qin Yahan put away the barrier.

Where did this rumbling sound come from? Why did it ring at the same time as his own machine? Moreover, this sound sounded like a machine, but not a machine