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

Sun Yiran said that breaking through to the Golden Core stage was difficult, and Shen Yifei knew this very well. He was currently in the mid-Foundation Establishment stage, two minor realms away from the Golden Core stage. With good luck, he could reach it in three to five years. With bad luck, being stuck for ten or eight years was common.

"Senior Sister Sun, the two methods you mentioned are both incredibly difficult." He picked up his teacup and took a sip. "Elders at the Nascent Soul stage? I'm just a woodcutter who doesn't even give me a second glance. As for cultivating to the Golden Core stage, who knows when that will ever happen."

Sun Yiran stared at him and smiled, "There's another way, which I haven't mentioned."

"What method?"

"You helped me break through to the mid-stage of the Golden Core realm, so I should repay you." She paused, a hint of a smile flashing in her phoenix eyes. "The cultivation technique I practice is called the 'Mysterious Yin Technique,' a rare orthodox technique in the Joyful Union Sect that doesn't rely on 'sexual cultivation.' But this technique has a unique characteristic—when Yin and Yang are in harmony, the cultivation speed is significantly faster."

Shen Yifei understood the implication in her words, "Senior Sister Sun, you mean...?"

"What I mean is, rather than letting you be targeted by those women who exploit you, I'd rather strike first." Sun Yiran stood up, walked around the table, and sat down next to him. "You help me break through, and I'll help you solidify your foundation. It's a fair trade; neither of us owes the other anything."

She was very close, and she had a faint woman's fragrance about her. In the secret realm, in that environment, Shen Yifei didn't notice her.

"Senior Sister Sun, didn't you say that the female cultivators of the Joyful Union Sect looked at me like I was a medicinal pill? Your gaze is almost the same now."

Sun Yiran was amused by him and gently pinched him: "Stop being silly, I'm different from them. They want to drain you dry, I want to help you. You help me cultivate, I'll help you improve."

Sun Yiran stood up, reached out and grabbed his wrist, "Come on, stop talking nonsense."

Shen Yifei was pulled towards the bedroom by her, feeling both expectant and amused. This Senior Sister Sun, though seemingly quiet and gentle, was more decisive than him in her actions.

Once inside the bedroom, Sun Yiran released her grip and turned to look at him.

"Junior Brother Shen, there's something I need to make clear to you."

"What is it?"

"The 'Mysterious Yin Technique' I cultivate emphasizes the balance of Yin and Yang, not the exploitation of other practitioners. So you don't need to worry about being drained dry by me." She paused, a faint blush rising to her face, "But there is a side effect."

"What side effects?"

"After dual cultivation, my spiritual energy will remain in your body for a period of time. During this time, your cultivation speed will be much faster than usual. But it will also... make the medicinal fragrance on your body stronger."

Shen Yifei was stunned for a moment, then realized what was going on. A stronger medicinal fragrance meant it would be easier to attract bees and butterflies, and easier for female cultivators to lose control.

"Wouldn't that make things even more complicated?"

"It's troublesome, but the benefits are great too. It all depends on how you use it!" Sun Yiran walked over and reached out to untie his belt. "You decide for yourself."

Shen Yifei thought about it and decided it was a worthwhile deal. The difference between a slightly stronger or weaker medicinal scent on him wouldn't make much difference, since he couldn't smell it anyway.

But being able to increase one's cultivation speed is a real benefit.

"Okay, let's give it a try."

Sun Yiran smiled, her eyes crinkling with laughter, a stark contrast to her usual dignified demeanor.

"Junior Brother Shen, that time in the secret realm truly opened my eyes!"

Shen Yifei looked up at her. The candlelight illuminated her face, making her not-so-pretty face look exceptionally pleasing to the eye.

"Senior sister, you're actually very beautiful!"

Sun Yiran suddenly laughed and said, "You look honest, but you're actually full of bad ideas."

Sun Yiran's Profound Yin Technique was indeed different from the cultivation techniques of the Hehuan Sect. When it was activated, spiritual energy flowed back and forth between the two of them.

Shen Yifei felt the liquid spiritual energy in his dantian slowly increasing, at a rate more than twice as fast as usual.

"Can you feel it?" Sun Yiran nestled against his chest.

"Hmm. The spiritual energy within you circulated around me, and it seems to have returned with something extra."

"That's natural. The 'Mysterious Yin Technique' emphasizes the harmony of Yin and Yang, where each contains the other. The spiritual energy generated by the fusion of your Yang energy and my Yin energy is far greater than that produced by cultivating alone."

Shen Yifei pondered for a moment and found this cultivation method quite interesting. No extraction, no replenishment, just mutual benefit—this was the proper way to practice dual cultivation.

"Senior Sister Sun, could you teach me this cultivation technique?"

Sun Yiran looked up at him and asked, "You want to learn?"

"Hmm. I'm currently practicing the Yin-Yang Absorption Technique, but that thing is too evil and can kill people easily. Your technique is much gentler."

Sun Yiran thought for a moment and nodded: "Okay, I'll teach you. But there's one condition."

"What are the conditions?"

"You can't refuse when I ask you to cultivate together in the future."

Shen Yifei chuckled: "These are the conditions?"

"These are the conditions." Sun Yiran leaned back. "What kind of good job do you think this is? Cultivating with you will speed up my cultivation, but you will also absorb some of the yin energy in my body. If it weren't for the medicinal fragrance on your body that can help me break through my bottleneck, I wouldn't do this kind of losing deal."

Shen Yifei held her close, feeling a warm glow in his heart. Sun Yiran was a straightforward person, never hiding anything, making her easy to get along with.

"Okay, deal."

The two lingered for a while longer, and it was almost dawn when Shen Yifei finally got up and got dressed.

Sun Yiran watched him get dressed and suddenly said, "Junior Brother Shen, be careful of Han Zhengli. I know that person. He lost face in front of Elder Gu, so he'll definitely come after you. He won't dare to do it openly, but he'll sabotage you in secret, and it's impossible to guard against him."

"I know." Shen Yifei finished fastening his clothes, turned to look at her, and said, "Senior Sister Su said to keep an eye on him for me."

"Su Yao?" Sun Yiran frowned slightly. "She didn't help you for nothing, did she?"

"Let me help her refine pills."

Sun Yiran nodded and didn't say anything more. Shen Yifei walked to the door and glanced back at her. Sun Yiran had already closed her eyes, her breathing even, as if she were asleep. She was exhausted from all the ups and downs of the night.

After leaving Sun Yiran's courtyard, Shen Yifei walked along the path towards his residence. He hadn't gone far when he sensed something was wrong.

He slowed his pace and touched the Cauldron of All Things.

"Little one, there's someone ahead." Liu Mengli's voice rang in his mind.

"several?"

"One. Mid-stage Golden Core."

Shen Yifei's heart sank. Mid-stage Golden Core? Could it be Han Zhengli? Could this guy have been following him all along?

A figure emerged from the fog ahead. It was indeed Han Zhengli.

He changed into a black outfit, with a long sword hanging at his waist. His face was gloomy, and his eyes were sunken, indicating that he hadn't slept well for several days.

"Junior Brother Shen, you're out of Senior Sister Sun's so early?" Han Zhengli's voice was sarcastic. "You served her well last night, didn't you? Senior Sister Sun is a mid-stage Golden Core cultivator, and you're only a mid-stage Foundation Establishment cultivator. You weren't drained dry?"

Shen Yifei didn't reply. This person was looking for trouble; whatever he said would be wrong.

Han Zhengli took two steps forward, his aura as a mid-stage Golden Core cultivator pressing down on him.

"Junior Brother Shen, you're quite capable. You were at the early Foundation Establishment stage before entering the secret realm, and you came out at the mid-stage. What good stuff did you get inside? Show it to your senior brother!"