I was Caught up in a Hero Summoning, but that World is at Peace (WN) - Chapter 2179: Birthday Gift Draw

Li Zhizhi was taken back to the capital at the age of fifteen to recognize her ancestral roots. As the true eldest daughter of the Li family, she should have been cherished. However, everyone preferred Li Suwan, who was knowledgeable, polite, and clever. As for Li Zhizhi, she grew up in a remote and impoverished village, ignorant of the ways of the world, and her name even carried a sense of disdain.

Traveling to the wizarding world, Eli found that he was an Eternal.

Life is infinite, life is immortal.

“What? The talent is very poor, then I will meditate for ten years, centuries, and thousands of years, and I can always meet the promotion requirements.”

“This skill is hard? Oh, let me study it for decades to see if it’s really that hard?”

“Consuming life force, improving mental force, and this kind of good thing.”

“The enemy is here? Oh, let me find a place to hide for a thousand years, until his lifespan is exhausted and his mental power dissipates, and then I will come out again, free and endless void.”

…

This is the story of an immortal who lives in the wizarding world and then kills the endless world.

- Description from novelbuddy

16 years old-- most boys would be falling in love, as their hormones all rise to unprecedented levels. Most boys at Riley's age would have dreams; dreams that will slowly grow into passion. Riley, however, at age 16... killed the world's number 1 superhero.