After activating his enlightenment, Gu Yi's alchemy skills had improved by a great deal in disguise. Refining the fourth-grade high-tier Bone Tempering Spirit Blood Pill was no longer difficult for him, and the entire process went smoothly.
Using the Singular Velvet Sky Chrysanthemum and Crimson Blood Ginseng, two "immortal-grade" medicinal herbs, along with other rare herbs as supplementary ingredients, Gu Yi refined three pills in a single batch.
—Quite a bit of Medicinal Liquid had been consumed by the scorching heat during Pill Fusion.
Otherwise, two Immortal Herbs and more than twenty rare medicinal herbs should have produced at least six or seven pills.
This problem became even more severe when he refined the Infernal Delicate Apricot and Octagonal Mysterious Ice Grass into the fifth-grade Yin Yang Limitless Pill. Gu Yi could clearly feel himself struggling.
After all, his true alchemy level was only fourth-grade low-tier. Crossing an entire major grade to refine a fifth-grade pill was naturally far more difficult.
The process of extracting the Medicinal Liquid was fine, and everything proceeded normally. Gu Yi controlled Purple Fire and refined the two Immortal Herbs into Medicinal Liquid one after the other.
However, during Pill Fusion, the Infernal Delicate Apricot and Octagonal Mysterious Ice Grass were both highly poisonous, and one was fire while the other was ice. Their properties were completely opposed.
To turn them into a pill, he had to use the principle of yin and yang counteracting each other, along with the other medicinal herbs, to first neutralize their toxicity into medicinal properties. Naturally, the difficulty of fusion soared.
To ensure the pill's success, Gu Yi could only increase the effects of enlightenment, consuming dozens of points of source power each minute to further enhance his comprehension, perception, and more.
Only then did he stabilize the Pill