Demon Cores, Demon Nascent Souls, and the Ruins Sea Crisis

These fifth-tier demon beast hides were not of particularly high grade. Only two were mid-grade fifth-tier; the rest were all low-grade fifth-tier.

They could only be used to draw low-grade and mid-grade fifth-tier talismans.

"However... if they can be nurtured for several decades like that cold-attributed demon core, these mid-grade fifth-tier demon beast hides should barely be able to transform spiritually into high-grade fifth-tier hides..."

Wei Tu pondered inwardly as he opened the True Interpretation of Formation Dao left behind by Island Lord Ye. His gaze settled on a formation called the "Four-Yin Spirit-Nurturing Formation."

If he had guessed correctly, the mid-stage fifth-tier cold-attributed demon core that had served as the grand finale at the black-market auction was the spiritual item Island Lord Ye had obtained after using this Four-Yin Spirit-Nurturing Formation to nurture an early-stage fourth-tier demon core for more than a century.

This method resembled the way cultivators nurtured their magic treasures, except it entrusted the tedious process of nurturing spiritual items to a formation.

In the Spirit Realm, a method like this that helped spiritual items "break through their tier" would undoubtedly be a tremendous loss—nurturing spiritual items required a vast quantity of spirit crystals, making it a thoroughly unprofitable endeavor.

Yet in the Human Realm, for a Spirit Transformation powerhouse like him, this method was an incomparably precious supreme art.

What he lacked were high-grade spiritual items, not low-grade spirit crystals.

Great Snow Mountain was a sect worthy of Wei Tu's trust. After considering it, he sought out Heaven-Brow Snow Lady, who was cultivating within the sect. After obtaining from her the right to access Great Snow Mountain's subterranean spirit vein, he set up several Four-Yin Spirit-Nurturing Formations near the sect's spirit vein to raise the grades of these demon beast hides, bringing them to mid-grade