In his Jin Qiao Peak Cave Mansion, Lin Yi started to refine the Foundation Building Pill using the alchemy furnace. The furnace he used was not a typical one fueled by spiritual wood.
Instead, it was an inferior-grade spirit furnace that had been used for many years, which he had asked his senior brother Wu Tian Zhang from the Pill Hall to purchase on his behalf.
A spirit furnace, falling under the category of spiritual artifacts, is way more expensive than ordinary flying swords. Even though this spirit furnace had been used by the Pill Hall for many years, its price was still nearly over ten thousand spirit stones. Even so, this was a discounted price considering his status as a direct disciple.
