554 Profound Heavenly Escape

On the second floor of the inn, Chen Fei sat flipping a piece of Yulin Stone in his hand, his eyes watching the hustle and bustle of the street below.

The Yulin Stone was something Chen Fei had just bought specifically. Besides the Yulin Stone, he had also purchased some other spiritual materials.

The price wasn't overly expensive, but the channels for purchasing were rather limited.

Just like the Yulin Stone in Chen Fei's hand, it was actually an auxiliary material that could be added when refining spiritual tools, capable of enhancing the toughness of the spiritual tool.

As for its other uses, they were actually quite few, and it wasn't always necessary to add such auxiliary materials during refining; they were more of a luxury than a necessity.