Toaru Majutsu no Index: Genesis Testament - Volume 2, Chapter 1: This is the Real Battle — Home_Ground_Hospital.

Shuu is a member of the literary club that can’t write. One day, he gets a mysterious message on his phone from a girl called Eina, and from that impulsive contact, they begin to exchange messages. They talk of things like their shared interest in novels and grow close. However, when they try and meet, they discover a shocking truth. Eina lives… not in the present, but five years in the past! How will their love develop, parted by five years of nights…!?

Zheng Tan somehow returns to the year 2003, turning into a black cat. Picked up from a rubbish heap by the Jiao family, he is given the name “Charcoal”, and so begins the life inside Professor Jiao’s family. Zheng Tan remembers that he was once a person, but currently his body is that of a cat. He has no way of speaking the human language, but can understand it, and even retains the thinking and IQ of a young 20 year old youth. Read along as he adapts to this new world, and somehow tumbles from a group brawl to catching a thief.

- Description from Novelupdates

Age difference of 700 years, vampire theme, cultivation, grammatical
This article is also known as “How to fall in love with an arrogant and abstinent old man”
That day, the girl was picked up by Mu’s house, covered in scars.
Everyone wondered, Mu Fei was so arrogant and cold, how could he accept such a small stutter.
The cold-hearted hostess felt a headache, “When are you going to follow me.”
“You, like, flowers, I, I think, for you.”
The girl’s heart was full of affection, and her little scarred hand held a bunch of purple flowers and handed it to the sweetheart who only belonged to the darkness.
An awards ceremony ten years later
Someone asked her: Why does Miss You always cover her neck every time she shows up?
You Ran’s expression was subtle, and he could only explain lightly: “I’m probably afraid of the cold.”
In fact, she was also helpless.
After all, the adult she admired was a cold-blooded clan who had lived for more than seven hundred years and was picky and obsessed with cleanliness. His greatest hobby was—
bit her neck with fangs,
Leave that exclusive bite/mark mark.
Even if the painful tears fell, she was willing to make each other’s blood-fed desserts.
Because she will be her nightingale in the end.

“On her lips is what my heart desires”
One-sentence introduction: After the pure complex stammering poor cub (true boss) was picked up by the high-cold abstinence blood clan, the romantic love story of “the following crime”.

Instructions for reading:
1. Abstinence, arrogant vampire noble x stunner in the world, crazily criticizing beauty
2. Mr. Mu Fei has two little hobbies: biting Yu and his neck; watching plays and movies.
3. This article is empty, the background is private, and the dark color of Cthulhu, please do not delve into it.
4. Two-way sweet pet/master/servant/cultivation/birth/age difference 700 years old/HE
5. Scarf @ Xia Sugar Suxi

Content tags: strong, soft spot, blood family, cool text
Search keywords: Protagonist: Mu Fei, You Ran ┃ Supporting role: ┃ Others: “Human” x Vampire, contrast cute
One-sentence introduction: innocent and crazy criticizing stunner & arrogant abstinence blood family
Intention: Firmly believe in the sun.

- Description from novelbuddy

The hellhound is a legendary beast known for its fierce loyalty and formidable power, serving as a guardian of the underworld. During a cataclysmic cosmic conflict between gods and devils, the hellhound is tragically killed as collateral damage, his life extinguished in a battle far beyond his control.Millennia later, the hellhound is reincarnated as a human, awakening in a world that has forgotten his true nature. Retaining his past abilities, he must now attend a prestigious academy for those possessing supernatural powers, designed to train the next generation of guardians and warriors.As he navigates the complexities of human emotions and relationships, he must also confront the remnants of his past life. Whispers of the cosmic conflict still linger, and dark forces are at play, threatening to disrupt the fragile balance between realms. In a world where alliances are fragile and danger lurks around every corner, he must learn to embrace his identity as both a hellhound and a human.