Chương 371: Chapter 370: Secret Technique: Sword of Thunder

After flying out of Glowing Valley, Black Oil Dragon Ross continued to fly north along the Mountain River Trade Route, the pervasive wind and snow could not block its vision or perception.

For a Bipedal Flying Dragon capable of sensing Cold Spring Point, foggy snow plains of hundreds of kilometers and clear warm lands are no different.

"Polly, it seems we haven't tested out our current speeds, have we?" Flying was always boring, Russell suddenly proposed, "How about we test it now?"

"Okay."

In an instant, the Mark of the Thunder Lord transformed into Unicorn Polly, and then Polly spread her massive wings, with storm and thunder rising beneath them, and she took off like a bolt of lightning.

In the blink of an eye, she disappeared from Russell's view, then, like a streak of lightning coming from afar, she returned to Ross's side.

"Faster than the speed of sound, Russell, my speed has now exceeded the speed of sound!" Polly excitedly expressed.

There was no sonic boom.