C1616 Stone of the soul

The soul force in the Undead Crystals was indeed extremely pure, because undead did not have many thoughts. Even if they had their own thoughts, they were still relatively simple. Furthermore, Undead Crystals was born within the Fire Seed of the Undead, which was the same as being refined by the Undead Flame at any time. Therefore, the purity of the crystal was unimaginable