He dared to lead the way even though he had no sense of direction?

"Black Tortoise stone? why haven't I heard of it?" Elder Qiu asked in confusion.

In order to find a way to restore the Zen Heart Stone, he had also been to the Sutra library. However, he didn't know how to forge weapons. Even the forging technique he had now was something he had learned halfway through his life in order to restore the Zen Heart Stone. Thus, even if he had seen it at that time, he wouldn't have paid much attention to it and would have overlooked it if he had been careless.

More importantly, he had lived for so long, but he had never heard of Black Tortoise stone.

"Black Tortoise stone can ignore laws and has the ability to reverse the universe and reset yin and yang. It has a miraculous effect on repairing spirit weapons. No matter what spirit weapon it is, no matter how badly damaged it is, it can be Reforged by Black Tortoise stone and restored to its original state." Ling Chuxi said without missing a single word, according to the records.