Naruto: I'm Nine-Tails and My Host is Kushina - Chapter 145

Others treated disease to save person, he treated disease to steal heart.

The Frost Goddess was deeply captivated by him. The gentle and kind beautiful teacher was completely enchanted by him. Even the cold and beautiful female assassin melted quietly because of him.

Competing in medical skills? He was the one who treated the Godly Doctor. Competing with backgrounds? Leaders rushed to him. What? You actually wanted to compete with him in a match for match? Looking at the gentle girl beside him, Tang Yu had a headache as he said, “Beautiful girl, how did you fall in love with me?”

- Description from Novelupdates

He’s the apathetic, sinister school prince, she’s the silly, joyous new student.

When the simple girl meets the sharp-tongued boy——

Gu Zichen: “Su Niannian, are you a pig!!!”

Su Niannian: “….can you communicate properly, and not attack people like this? Even if I am a pig, then I’m a precious and unique pig!”

When the wounded girl wants to escape from the oppressive boy——

“Caring for precious animals is my duty.” Merely one heartless sentence, and he carries her directly home.

But why did he need to care for her all the way to bed, hey!!!

- Description from Novelupdates

“Hmph, my dumb big sister is in danger!” A mischievous grin spread across his face. “Hehehehe... this gives me the perfect excuse to finally use this treasure I’ve acquired but never bothered with!” He rummaged through his belongings, carefully selecting various items. “A bit of this... and this... and a dash of this.” Boom! The explosion of energy sent a ripple through the air as he laughed maniacally. “Hahaha! It’s done! Now, all I need is a compatible host for it.” Years later... “Did I overdo it?” he wondered in awe, watching as his creation wreaked havoc, conquering world after world with ease, as though stealing candies from children.

I finally managed to kill the demon lord.