Transmigrated into Li Chengqian, he effortlessly ascended the throne and became emperor.

As the water clock dripped away, moonlight streamed through the carved window frames, casting a cool, frosty white glow on the golden brick floor of the Prince of Qin's mansion.

The indoor heating system was burning brightly, filling the air with a bitter medicinal aroma and a faint calming fragrance.

Deep within layers of curtains, Empress Zhangsun had been sitting in the same position by the couch for almost two hours.

She changed the silk handkerchief in her hand one after another, her hand trembling slightly each time she reached for her son's forehead, until the burning heat under her palm finally showed signs of subsiding. Only then did Empress Zhangsun lean weakly against the bedpost, as if her spine had been removed.

"Amitabha..." she murmured softly, tears still wet at the corners of her eyes.

On the couch, five-year-old Li Chengqian nestled in the soft silk quilt, a tiny, fragile figure that seemed as if it would shatter at the slightest touch.

Although he was asleep, his brows were still slightly furrowed, as if he had suffered great injustice in his dream.

Li Chengqian's consciousness gradually returned. He did not open his eyes immediately, but instead uttered a very soft and delicate murmur: "...water."

Her voice was hoarse, with a soft, sleepy tone.

This command is more effective than an imperial edict.

Empress Zhangsun sat up almost instantly, disregarding her manners, and hurriedly picked up the warm honey water that had been sitting on the table. She carefully scooped up a little with a silver spoon and brought it to her son's lips.

"Chengqian? Chengqian, you're awake? Come, let your mother feed you, drink slowly."

The warm honey water flowed down my throat, relieving my burning thirst.

Li Chengqian slowly opened his eyes, his pupils shining black, reflecting Empress Zhangsun's haggard face.

Instead of bowing properly as usual, he just stared blankly at his mother, his eyes carrying a perfect blend of unfamiliarity and bewilderment.

"Mother..."

He shrank his neck, burying half his face in the blanket, leaving only his wet eyes showing. "You're still here? I thought... I thought Mother didn't want me anymore and went to be with Qingque."

Qingque was the nickname of Li Tai, Li Chengqian's younger brother from the same mother.

Li Tai was only one year younger than him, and was round and cute. He was deeply favored by Li Shimin and was Li Chengqian's biggest rival in the struggle for the throne in history.

Upon hearing the name, Empress Zhangsun's hand trembled, and the silver spoon clattered against the porcelain bowl with a crisp sound.

"What nonsense are you talking about?" Empress Zhangsun's eyes reddened. She put down her bowl, reached out to touch her son's face, and said in a voice full of bitterness, "You are my son, the flesh of my body. How could I abandon you?"

Li Chengqian tilted his head slightly and obediently rubbed against Empress Zhangsun's palm, like a cat seeking comfort.

But the words he uttered were increasingly hurtful.

"But... Qingque is smarter than me."

The little child lowered his eyes, his long eyelashes trembling. There was no jealousy in his tone, only a sense of resigned loss and self-loathing.

"Qingque can memorize the poems the teacher teaches after reading them three times, but I have to read them ten times. Every time Father tests my studies, he smiles when he sees Qingque and praises him as a thoroughbred. But when he sees me... Father always frowns."

"Mother, am I stupid? Is it because I'm not as clever as Qingque that Father doesn't take me with him and leaves me alone in the mansion?"

"No! That's not how it is!"

Empress Zhangsun felt her heart was breaking.

She always thought her eldest son was calm, intelligent and sensible, so she strictly demanded that he meet the standards of a crown prince, and usually tested his knowledge and taught him etiquette.

Little did she know that in the mind of this five-year-old child, her strictness would be interpreted as disdain.

"Your father is strict with you because you are the future heir apparent and the eldest brother..." Changsun Wugou explained palely.

"I know."

Li Chengqian interrupted his mother, his voice soft and thick with a nasal tone, "I am the eldest son, and I must set an example. I understand."

He sniffed, stretched out his slightly cool little hand, and gently grasped Changsun Wugou's sleeve, his knuckles turning white.

"Mother, I'm not jealous of Qingque. Really."

He forced a smile that looked more like a grimace, a smile that seemed to stab Empress Changsun in the heart. "Qingque is so cute, I like Qingque too. I just... I'm just a little envious of him."

"What do you envy about him?" Empress Zhangsun asked subconsciously.

Li Chengqian lowered his head, his fingers unconsciously twisting the gold thread on the quilt, his voice barely audible:

"I envy him for having a name."

Empress Zhangsun was taken aback. "Why? The name Chengqian was personally chosen by your grandfather. It's so precious..."

That's his real name.

Li Chengqian suddenly raised his head, and tears finally rolled down his pale cheeks, dripping onto the embroidered python pattern on the quilt, spreading into a dark little flower.

"My father calls my younger brother Qingque. When he's happy, he'll hug Qingque and call him Aque or Fat Sparrow."

"But Mother..."

Little Li Chengqian broke down in tears, his voice filled with endless grievances:

"Growing up like this, my father has never called me 'godson' even once. Never."

As Empress Zhangsun looked at her son, who was crying uncontrollably, scenes from the past flashed before her eyes.

Yes.

From the moment Chengqian was born, high hopes were placed upon him.

Because he was born in Chengqian Palace, he was named Chengqian. However, this name was too grand and too heavy, making it hard for the child to breathe.

The couple were preoccupied with the future of the Tang Dynasty and the rise and fall of their family, forgetting that their eldest son was just a five-year-old child who longed for his parents' embrace and an affectionate nickname.

"My son—"

Empress Zhangsun hugged Li Chengqian tightly and burst into tears, "It's my fault, it's all my fault, I've neglected you."

Just then, a very faint sound came from outside the door.

It was the dull thud of brocade boots on the wooden floor, accompanied by a suppressed sigh.

Li Chengqian's ears twitched.

Someone is eavesdropping.

Who else could it be but Li Shimin, the master of the Qin Prince's Mansion?

Sure enough, the curtain was suddenly flung open by a large, bony hand.

A cold wind, carrying the chill of the heavy dew, swept into the room, causing the candlelight to flicker violently and casting Li Shimin's tall figure onto the screen, making him appear somewhat desolate.

This decisive and ruthless general on the battlefield had red eyes at this moment.

They had obviously been standing outside for a long time and had heard the entire conversation.

"Erlang..." Changsun Wugou raised her head with tears in her eyes.

Li Shimin did not speak; he strode to the bedside.

Li Chengqian, who was still sobbing, instinctively shrank into Empress Zhangsun's arms like a startled rabbit. He looked at Li Shimin timidly with a hint of flattery and fear, but no affection.

This subconscious dodge was like a heavy hammer blow to Li Shimin's heart.

What did I do to him that made him so timid and afraid to even ask for a nickname?

Li Shimin felt as if something was blocking his throat, causing a sour and unbearable sensation.

He slowly squatted down, his gaze level with that of his son on the bed.

"Chengqian." Li Shimin's voice was terribly hoarse.

Li Chengqian replied softly, "...Father, your son...your son knows he was wrong, your son shouldn't have spoken recklessly."

"No, you're not wrong. It's Father who's wrong."

Li Shimin reached out, wanting to touch his son's head, but hesitated halfway through, afraid of startling him again.

Finally, the large hand that held the power of the entire nation gently and tenderly landed on Li Chengqian's still feverish cheek.

The rough calluses on his fingertips brushed against Li Chengqian's delicate skin, sending a shiver down his spine.

"Your father always thinks that you are the older brother and you should set an example, but he forgets that you are only five years old."

Looking into his son's eyes, which resembled those of Empress Zhangsun, Li Shimin felt a surge of tenderness and guilt he had never felt before.

"Didn't you envy Qingque for having a nickname?"

Li Shimin took a deep breath, his gaze becoming incredibly firm and profound, as if he were making an extremely important decision.

"I'll give you a nickname too. A unique nickname that belongs only to you."

Li Chengqian blinked, revealing a hint of anticipation and disbelief: "Really...really?"

Li Shimin took out a piece of warm jade that he had worn for many years from his bosom and put it into Zhao Heng's hand, then wrapped his hands tightly around those cold little hands.

"You are your father and mother's eldest son, the hope to carry on the family line, but in your father's heart, you are his most treasured possession."

Li Shimin paused, his eyes full of affection, "From now on, in private, may your father call you Yunu?"

In this era, "slave" is not a derogatory term, but rather the most affectionate and unguarded term of endearment that parents use for their children.

Usually, only the youngest and most favored children receive this treatment, such as Li Zhi later on.

Li Chengqian's heart stirred slightly.

Those once dull peach blossom eyes suddenly burst forth with dazzling light, as if the entire starry sky had fallen into them.

Ignoring her feverish weakness, she suddenly broke free from Empress Zhangsun's embrace and buried her head in Li Shimin's broad chest.

"Ah!"

"Yu Nu likes it!"

Feeling the soft bundle in his arms, Li Shimin felt his heart melt, and his eyes even became a little moist.

He hugged his son tightly and rubbed his chin against the soft hair on his son's head.

"You are my father's jade slave, his most beloved son."