I Got Stronger By Using Copper Coins Until I Am Invincible - Chapter 393 - You Didn't Keep Your Promise!  

A fluffy, sweet modern GL story about a mature older women and a cute university student.

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

The Revered Master, Yu Yan, known as the number one in the cultivation world, waited for sixteen thousand years, and finally took in a disciple. He taught her carefully, and took care of her diligently. He watched her as she slowly grew stronger as she comprehended the laws, and just as she was about to soar into prominence… she died!

Alex was an ordinary teenager—until the day he discovered his ability to drain energy from the dead. With powers rooted in death itself, Alex hides his necromancy behind a normal life, secretly entering deadly portals to fight monsters and earn money. But beneath the surface, a darker truth lingers—his parents's death and his powers are linkedAs he harnesses his necromantic abilities, draining the fallen to grow stronger, the weight of his power begins to take its toll—and the line between the living and the dead starts to blur.With enemies closing in and betrayal around every corner, Alex must master his growing abilities before they consume him—or worse, before the forces hunting him claim everything he has left.When death becomes your greatest weapon, how long can you survive before it turns against you?---