The Hehuan Sect cultivates alchemy; my senior sister helps me refine alchemy throughout the world.

The next morning, Shen Yifei pushed open the door and came out. Song Hongliao was already standing outside the courtyard.

Today she changed into a light blue dress, her ponytail was still tied high, and the two short knives at her waist had been replaced with two long swords, the copper rings on the scabbards still jingling.

"Hey, Butler Song, up so early? Why the change of gear? Are you going to gouge my eyes out again today?"

"Hmph, my sword can be long or short, hard or soft, it can become whatever it's suitable for cutting."

"Hmm, this thing of yours is pretty good. It would be incredibly useful with a retractable scabbard!"

Song Hongliao didn't understand what he meant. "Let's see if my sword has a chance to cut your tongue today. You've got a real tongue-lashing!"

Shen Yifei pretended to be scared and quickly shut his mouth.

Seeing his discomfiture, Song Hongliao curled her lips into a slight smile. "My senior sister wants you to come over!"

After saying that, he turned and left.

Along the way, her ponytail swung, her two long swords crossed behind her waist, and the copper rings jingled all the way.

Upon arriving at the main hall, Song Hongliao pushed open the door and went inside, with Shen Yifei following behind her.

Gu Yunyan remained as lazy as ever, slumped in her chair with one leg resting on the armrest.

Today she changed into a deep purple dress with an even lower neckline, revealing a deep cleavage below her collarbone, showcasing her proud and masculine figure.

"You're here?" Gu Yunyan raised her chin. "Hongliao, you can go out now."

Song Hongliao glanced at Shen Yifei, then turned and left. The door closed behind her, leaving only the two of them in the hall.

"Sit down," Gu Yunyan said, pointing to the chair next to her.

"Tell me, what are your plans regarding the Demon Core?"

Shen Yifei thought for a moment, "Sect Master, you have to let me see what the Demonic Essence looks like first."

Gu Yunyan stretched out her hand, palm facing up.

A wisp of black energy emerged from her palm, like a small snake, coiling around her fingertips. The energy was as black as ink, and looked ominous.

Shen Yifei stared at that wisp of demonic energy for a long time.

"It's definitely different from spiritual energy. Spiritual energy is transparent, but yours has its own color."

"Demonic energy has attributes. My cultivation method produces the dark attribute, hence its black color." Gu Yunyan put away her demonic energy. "How can you refine pills if you don't have demonic energy within you?"

Shen Yifei pretended to think for a moment, then said, "If the Sect Master doesn't mind, try channeling demonic energy into my body. As long as there is demonic energy within me, I can refine demonic pills!"

"Injecting demonic energy into a cultivator's body?" Gu Yunyan laughed. "Are you genuinely unaware of the meaning of death, or are you feigning ignorance?"

"Sect Master, I value my life very much and wouldn't joke around with it." Shen Yifei stood up and walked to her. "Just give me a little bit, just a little. If I can't handle it, you can take it back. You're at the Tribulation Transcending stage; controlling this little bit of demonic energy is a piece of cake for you."

Gu Yunyan stared at him for a long time, wishing she could see through all the tricks and schemes in Shen Yifei's mind.

But how dare someone at the early stage of the Nascent Soul realm challenge a master at the Tribulation Transcending realm? Is this kid up to some kind of scheme?

Forget about any tricks; in the face of strength, everything is in vain!

Gu Yunyan extended her index finger, a wisp of black energy condensing at the tip, and pointed it towards Shen Yifei's brow.

Shen Yifei did not dodge.

The black energy seeped into the space between the eyebrows and traveled down the meridians.

That power was completely different from spiritual energy. Spiritual energy is warm, while demonic energy is cold. It wasn't the coldness of Su Wuwang's pure Yin energy, but a different kind of coldness with a sinister feel.

Shen Yifei shuddered.

"If you can't handle it, just say so." Gu Yunyan withdrew her finger. "You don't have a foundation of demonic energy in your body. Forcing it to remain will erode your meridians. At best, your cultivation will regress; at worst, you'll suffer a qi deviation."

Shen Yifei closed his eyes and sensed it. The black energy circulated through his meridians and finally settled in his dantian.

The dark golden spiritual energy in his dantian seemed to be stimulated, and suddenly shrank into a ball, surrounding the black energy in the middle.

The black energy, enveloped by the spiritual energy, struggled to break free but couldn't escape. It gradually calmed down, retreating to a corner of the dantian, keeping to itself and the spiritual energy at peace.

"Is it all done?" Gu Yunyan was a little surprised to see him open his eyes.

"Alright." Shen Yifei looked down at his dantian. "Your wisp of black energy is staying in my dantian, it's not causing any trouble."

Gu Yunyan stood up and walked in front of him, placing her hand on his lower abdomen. Her palm pressed against his skin, and demonic energy probed in, circulating within his dantian.

She withdrew her hand, and the expression on her face changed.

"Can your dantian hold demonic energy?"

"It seems so." Shen Yifei grinned. "I'm not good at anything else, but I'm good at pretending. I can pretend to have spiritual energy, and I can pretend to have demonic energy too."

Gu Yunyan stared at him for a few moments, then extended two fingers. This time, it wasn't one wisp, but two wisps of black energy that simultaneously entered his brow.

Shen Yifei shuddered again, more violently than before. Two streams of black energy surged and crashed through his meridians, causing him to sweat profusely from the pain.

Dark golden spiritual energy surged from the dantian, enveloping the two streams of black energy and dragging them back. The black energy struggled a few times, then was pulled into the dantian, shrinking next to the wisp of black energy from before.

Three wisps of black energy squeezed together, like three small black snakes coiled up.

Gu Yunyan then reached out and pressed her hand on his lower abdomen, probing it.

A look of surprise crossed his face. "You didn't practice demonic arts too, did you?"

"Sect Master, do you think that's possible? Maybe it's just that my dantian is special, able to hold anything. To be honest, I've also refined demonic energy."

"I never expected you to be a cultivation monster! Spiritual energy and demonic energy coexist without conflict. I've never seen anything like it in all my years of life."

"Sect Master, I noticed there were a lot of impurities in the demonic energy you input just now. Has your cultivation level been stuck for many years?"

"You could even tell that?"

Shen Yifei rubbed his dantian area. "Sect Master, those two strands of demonic energy you just drank had three parts demonic energy and seven parts impurities. It's like drinking muddy water; it quenches your thirst, but leaves you with a mouthful of sand."

Shen Yifei's analogy was a bit crude, but Gu Yunyan understood the point immediately. She had been stuck at the early stage of the Tribulation Transcending Realm for who knows how many years, and no matter how she cultivated, she could not improve at all.

The problem lies here, like a spring blocked by silt; how can it possibly flow?

"You're right. I've been stuck at the early stage of the Tribulation Transcending Realm for two hundred years. No matter how hard I try, my cultivation level can't be improved any further! Do you have any way to help me?"

"I have a way." Shen Yifei grinned. "Sect Master, when you input your demonic energy, I can refine it and feed it back to you!"

"You mean, if I give you my demonic energy, I can cleanse the impurities inside?"

"If the sect leader doesn't believe us, we can give it a small test. If you find it useful, clean a little bit every day. Little by little, it will help you clean away all the impurities!"

After listening, Gu Yunyan fell into deep thought. This temptation was even greater than refining the magic pill.

If what this kid says is true, then the cultivation problem that has troubled me for hundreds of years will be solved.

However, she also understood that this was actually the dual cultivation of spiritual energy practiced by the Hehuan Sect. If he wanted to drain her demonic energy, she would be completely crippled!

I have no idea what this kid is up to. Does he genuinely want to help me, or does he want to drain me dry?

Seeing her hesitation, Shen Yifei knew what she was worried about.

"Sect Master, your demonic energy is powerful. My dantian can withstand even a trace of it, but if too much floods in at once, I definitely won't be able to handle it, and I might even explode!"

Gu Yunyan nodded slightly. Shen Yifei's words made a lot of sense. In this kind of dual cultivation where the details were unknown, only if each person grasped the other's lifeline could problems be avoided.

"Okay, I believe you."