"Xiaoxiao, do you know about a fish that can cross between the Yin Yang Realms?"
Pei Yuhang's gentle voice was like a fishhook, pulling Yu Xiaoyan's wandering thoughts back to the present.
She glanced discreetly at her prim Senior Sister, who could only watch with envy. Then, Yu Xiaoyan burrowed even deeper into her Master's embrace, as if trying to meld her petite frame into his.
"A fish? What kind of fish?"
Perhaps because her entire face was buried in Pei Yuhang's chest, Yu Xiaoyan's voice came out muffled.
"In this world, there is a fish known as the 'Fishwife.' It can cross between the Yin Yang Realms. There are rumors that if you can find a Fishwife large enough, you can climb into its mouth and enter the Underworld as a living person."
"That's so amazing! Master, are you going to bring me a Fishwife?"
Listening to her Master's reassuring heartbeat, Yu Xiaoyan murmured sweetly.
"I plan to catch a Fishwife and have Elder Lu refine a Soul Splitting Pill for you. This elixir can purify the Divine Soul...
"Your 'sister' has been trapped in your body for too long. Now that your cultivation is approaching the Golden Core realm, you can withstand the elixir's power. It's time to let her move on to reincarnation.
"Once your Divine Soul has stabilized, crossing your Golden Core Celestial Tribulation should also be much smoother."
"..."
The moment Yu Xiaoyan heard her Master say he was going to separate her "sister" from her body, her small frame trembled involuntarily.
"What's wrong, Xiaoxiao?"
"...Master, my sister and I are incredibly close. I can't bear to lose her..."
Yu Xiaoyan hugged Pei Yuhang's waist tighter, her voice taking on a wheedling tone, hoping her Master would abandon the idea.
But Pei Yuhang's expression turned serious.
He looked at Yu Xiaoyan seriously and said, "Xiaoxiao, the Divine Soul is no laughing matter. As a Cultivator's cultivation deepens, their Great Dao Karmic Force grows heavier. The weaker the Divine Soul, the more susceptible one is to birthing a Heart Demon."
"Besides, your situation of having two souls in one body is extremely dangerous when Crossing the Tribulation. The Celestial Dao Will might treat you as two people and subject you to a double Celestial Tribulation..."
"I'm not afraid, Master!" For once, Yu Xiaoyan didn't go along with his wishes. She stubbornly met Pei Yuhang's gaze.
"This isn't a matter of whether you're afraid or not. For your own safety, you must separate your 'sister' from your body."
Having already watched his Dao Companion fail her tribulation and suffer grievous injuries, Pei Yuhang could not accept even the slightest chance of mishap when his own disciple was Crossing the Tribulation.
However, he wasn't an unreasonable Master.
Pei Yuhang's voice softened as he stroked Yu Xiaoyan's head.
"If you can't bear to part with your 'sister,' and if she doesn't want to enter reincarnation either, you could have her become your Sword Spirit.
"That way, she can stay with you forever, Xiaoxiao."
"..."
Yu Xiaoyan lowered her head, silent.
Pei Yuhang assumed she was upset, so he silently stroked his young disciple's hair, hoping she would eventually see reason.
But what Pei Yuhang couldn't see was how twisted and hideous Yu Xiaoyan's lowered, pretty face had become.
Despite possessing such a pure and innocent face, her expression was as terrifying as a Rakshasa's.
'Let that disgusting creature stay with me? How laughable. I wish that vile thing who calls herself my sister would have her Divine Soul utterly annihilated!'
'A disgusting thing like that... Who cares if she lives or dies?'
'But... but—'
'But without her, I would become useless.'
This was the secret Yu Xiaoyan had always hidden, a truth she could never, ever tell her Master.
When Pei Yuhang had first taken her as his disciple, he'd told her she possessed a Seven-Aperture Exquisite Heart. It was a talent for comprehension that was second to none, and as long as she developed smoothly, she could one day establish her own sect and become a Great Power who would leave her name in the annals of history.
But what Pei Yuhang didn't know was that the one who truly possessed the Seven-Aperture Exquisite Heart wasn't her, Yu Xiaoyan, but the "sister" she wished with every fiber of her being she could tear away.
It was only with her "sister's" help that Yu Xiaoyan's cultivation speed was so astonishing, allowing her to surpass Qing Yueqiu's Swordsmanship from when she was the same age.
Without her "sister's" help, on her own...
'I'd be left in my Senior Sister's dust forever. I'd become a complete nobody, forgotten in some nameless corner all over again.'
'I'd never have my Master's attention. I'd never have his warm embrace or his gentle touch.'
'Even worse... if Master ever realized the disciple he truly wanted was her "sister," he'd abandon me completely!'
'Just like back in the Capital City, when I was locked away in that dark, stuffy attic!'
'No, absolutely not!'
'I'd rather die than be abandoned by my Master.'
'That wretched wench... she has to stay inside my body.'
The corners of Yu Xiaoyan's mouth twitched, pulling into a pathological smile.
'It was all her "sister's" fault for destroying my happy life and taking away my beautiful home. Everything she was doing now was just compensation for what she owed me.'
'How could I possibly let her pass into reincarnation so easily?'
Pei Yuhang looked down at Yu Xiaoyan, frowning in confusion. Something seemed a little off.
'What's going on? Why has my young disciple's Divine Sense become so murky?'
"Xiaoxiao? Xiaoxiao?"
Pei Yuhang gently shook Yu Xiaoyan's shoulder, his voice full of concern.
Yu Xiaoyan froze for a moment before slowly raising her head. Her eyes were red-rimmed from crying, and her soft, tear-filled gaze was so pitifully lovely that it made one want to pull her into a protective embrace.
"Master... I really can't be separated from my sister! Xiaoyan wouldn't be whole without her! Please, just let my sister and me both be your disciples...!"
Yu Xiaoyan sobbed, and her vulnerable display was enough to move even Qing Yueqiu, who stood off to the side.
"Master, I often hear Little Junior Sister talking with her 'sister.' And she's said more than once that her 'sister' is the most important family she has..."
Qing Yueqiu added cautiously.
Yu Xiaoyan hadn't expected her normally stoic Senior Sister to suddenly speak up for her. Seizing the opportunity, she threw herself into Pei Yuhang's arms and burst into tears.
Her tears soaked the front of Pei Yuhang's robes.
In the end, his heart softened.
"...Alright. I really can't say no to you two."
"Separating the Divine Souls was to ensure you could cross the Celestial Tribulation safely. It's the simplest way to lower the tribulation's difficulty."
"But since you're unwilling, Xiaoxiao, then prepare to cultivate the magic for Divine Soul Fusion. Your Divine Soul will slowly merge with your sister's until the two are indistinguishable... Of course, even after the Divine Soul Fusion, your personalities will remain independent."
'Divine Soul Fusion?!'
The rosy color instantly drained from Yu Xiaoyan's face, leaving it deathly pale. Her lips trembled as a dry, raspy sound escaped them.
"Master, after the Divine Soul Fusion... does that mean my sister will be able to control my body?"
"Yes. From now on, you and your sister will have to agree on how to share time controlling the body.
"You can't have one of you cultivating all the time while the other just goofs off, you know."
Seeing how nervous Yu Xiaoyan looked, Pei Yuhang added the last part as a lighthearted joke.