Fang Han finally felt at ease—and only then turned his thoughts to other questions.

“You just collected that red liquid—that was theMang Gu Scarlet Toad’s venom?”

Cheng Lingsu nodded. “Mm. Although Master never found the creature himself back then, he gathered plenty of rumors and accounts, forming many hypotheses and conclusions. Quite a few of them match what we saw today.”

“As for collecting its venom—it’s quite simple.”

Fang Han silently thought:That’s only simple for you. For anyone else—even me—that would be nearly impossible.

Glancing at theMang Gu Scarlet Toadinside the little vine cage, he asked with uncertainty, “Will that thing stay trapped?”

Cheng Lingsu gently shook her head. “Probably not. Only temporarily.”

“TheMang Gu Scarlet Toad’s venom is too powerful. The vines I used to weave that cage, within moments of harvesting, have already begun to wither and yellow. I doubt they’ll last long before becoming brittle and breaking apart.”

“To truly contain it, I’ll need to craft something out of sturdier materials. But with things so rushed, this is the best I could do for now. But don’t worry, Brother Fang—I have it all planned.”

Fang Han nodded slightly. “As long as you have a plan.”

He was honestly quite delighted.

With theScarlet Toadin their hands, and with Cheng Lingsu’s abilities, it wasn’t just about creating highly potent poisons. Even the “Immunity to All Poisons” (bǎi dú bù qīn, 百毒不侵) he’d hoped for might become a real possibility.

After theScarlet Toadincident, Fang Han’s earlier desire to leave the mountain temporarily quieted down.

The two of them remained in the stone cave within the secluded valley for anotherhalf a year.

During that time, apart from the usual daily martial arts training, all their remaining hours were spent researching the venom of theMang Gu Scarlet Toad.

Well, Fang Han was mostly assisting and learning on the side.

Cheng Lingsu had far more free time than Fang Han, since now that he had thoroughly mastered the meridian circulation ofBeiming Divine Skilland could cultivate its inner force independently, she no longer needed to watch over him constantly.

It was worth noting that Cheng Lingsu hadnotbegun cultivatingBeiming Divine Skillherself.

Not because she didn’t want to—but simply because shecouldn’t.

Just like Fang Han, she already had internal energy within her, and thus was subject to the key restriction ofBeiming Divine Skill: one must abandon all prior inner cultivation.

Fang Han succeeded only becauseCheng Lingsu’s god-tier medical skillscould easily correct any misalignment of energy flow or meridian disturbance. Through constant trial and error, he eventually grew proficient and deeply familiar with the method.

But the reverse was not possible.

First, Fang Han’s medical skills weren’t up to par. He could not stabilize misfiring energy or treat chaotic meridians—not even close to the level where Cheng Lingsu could calmly resolve such crises.

So naturally, he couldn’t oversee her training.

And if Cheng Lingsu practiced alone, she risked falling into a life-threatening conflict of energy routes.

As the saying goes:“A healer cannot heal themselves”(yī zhě bù zì yī, 医者不自医)1. With her skill, Cheng Lingsu might manage minor issues, but facing instant, extreme crises, even she would be powerless.

After careful consideration, they agreed she shouldnottrain inBeiming Divine Skill.

Cheng Lingsu herself didn’t mind.

She’d never been especially interested in martial arts or divine techniques.

If she could train, great. If not, so be it.

Were it not for Fang Han’s deep passion for martial arts, which made her somewhat interested by extension, she likely would’ve just skimmed through the scrolls, seen the risk, and given up without further thought.

That said,she loved Lingbo Weibu.

Its elegant and advanced movement techniques suited her well. Even as a beginner, she made significant progress.

It was especially useful for climbing mountains to harvest herbs, and helpful for self-defense when traveling.

So in short, while Fang Han trained bothBeiming Divine SkillandLingbo Weibu, Cheng Lingsu focused solely on the latter, giving her much more time to spare.

She remained fascinated by theScarlet Toad—and since Fang Han had high hopes for its uses, her dedication doubled. Interest plus motivation from a loved one—how could she not give it her all?

Aside from essential daily routines, she devoted nearly all her time to researching theScarlet Toadand its crimson venom.

After six months, this brilliant and gifted young woman, blessed with an extraordinary affinity for medicine, finally succeeded in crafting a remarkable pill—

The Scarlet Toad Spirit Pill (朱蛤灵丹)!

Using the toad’s venom as themain ingredient, she combined it with seven or eight other rare toxins from Wuliang Mountain.

Then she used theSeven-Heart Begoniaas thecatalyst herb, merging all into a singular elixir.

It was called awondrous pill(qí dān, 奇丹) because every component wasextraordinarily poisonous. The crimson venom andSeven-Heart Begoniaalone were among the world’s deadliest.

Yet through Cheng Lingsu’s ingenious formulation, the toxins didn’t cancel each other, butneutralized and stabilizedwithin the pill.

Or more precisely, they weresuppressed and tamed.

She said: “Brother Fang, you once told me—Duan Chang Cao, Lightning Mink venom, the red centipede toxin, and finally swallowing theScarlet Toad—might lead to an immune-to-poison physique. I’ve been thinking about that these past few months.”

“It’s rare, but not impossible.”

“However, theorder of ingestion, theintervals between poisons, thestate of the body—any deviation in these could result in catastrophic failure. The scenario you described isextraordinarily rare—almost impossible!”

“But if we follow that train of thought… There may be a viable path.”

Fang Han looked at the pill in her palm—black with a faint red sheen—his heart filled with disbelief.

“Lingsu… you did it?”

Cheng Lingsu pursed her lips in a smile and playfully rolled her eyes. “Onlypreliminarysuccess. You know this as well as I do—alchemy is one thing, but until it’s tested, how can we call it a success? We still need to verify it. That could take a few months—maybe half a year.”

Fang Han sighed deeply. “In front of you, I truly can’t claim to understand medicine. Our Lingsu is amazing~”

Cheng Lingsu chuckled, and a faint blush colored her fair cheeks.

“Brother Fang, just wait a little longer. I’ll refine the pill soon.”

Fang Han nodded enthusiastically. “Wait? Of course I’ll wait!”

Footnotes

Source: Webnovel.com, updated by lotustale.com