Upon hearing Wally's words, He-Gu felt a shock in his heart and looked at him in surprise.

How could he know about Ore No. 0 metal!?

Even if he figured out that I use the marble to identify substitutes, how could he know the name "Ore No. 0 metal"!?

Wally's words immediately heightened He-Gu's sense of alertness, and various thoughts flashed quickly through his mind.