Baka to Test to Shoukanjuu‎ - Volume 12, The Thirteenth Question

"An accident. She's pregnant. How unlucky. She got pregnant in one shot!

Su Yao passed through and traveled to the Marvel world to become a mutant. He was still in the experimental base. He expressed a little panic…

Fortunately, at the critical moment, the mutant ability ‘imitation’ was awakened to imitate the opponent’s ability!
…
Imitation object→Orochi (title: Sun God, Will of the Earth)
Imitation object→Wanda (title: Scarlet Witch, owner of chaos magic)
Imitation object → Sun God…
…
Professor X: “We must find him as soon as possible and guide him to control his power to avoid causing irreparable disasters!”
Magneto: “You are my child???”
Thor: “Brother?”
Loki: “?”

- Description from novelbuddy

Meng Yu’s Golden Finger was called “Corruption Strengthens Tenfold, Becoming a Demon Strengthens Hundredfold,”both extremely fierce and convenient to use. “Those who consume Qi are divine and long-lived, constructing the foundation of ten-thousand generations, and on the day they achieve immortality (’Dan’), they break the self of yesteryears (’Infant’), transforming into heaven and earth, thus becoming immortals.” This is the eternally correct tale of the Qi Refinement Practitioner Meng Yu’s grand cultivation adventure.

Yuki, a high school junior, dies heroically saving a stranger and is reincarnated in a fantasy world, where he discovers an extraordinary and unrivaled power.