In the MCU/Marvel with the Omnitrix/Ultimatrix - Chapter 37: Recalibration

A man reincarnates in the body of a boy who suffered a tragedy, only to realize that he is in the world of My Hero Academia. What's even stranger is that his quirk seems to have the abilities of Nen and Haki.

A high-schooler who loves playing FPS games were reincarnated in the fantasy world. And usually, those who were isekaid were blessed with overpowered magic and a legendary beast. However, our main character is different.Instead of those things, he awakened a shop system where he could purchase American freedom! And since modern guns is as good as magic, he decided to make full use of this ability and make a name for himself in this new world.Fireball? Cute. My M203 grenade launcher makes a bigger boom.Summoned beast? That’s nice, I’ve got a UAV with thermal optics.You can split oceans with magic? Cool. I can erase cities with a nuke.Whatever overpowered spell you’ve got, I’ve got something better.

After millions of years spent hunting and battling, the forces of darkness were finally pushed back and eradicated. But as Twilight’s lifespan approached its inevitable end, he made a fateful choice—to reincarnate into the future, where a golden age was prophesied to unfold.Now reborn as Twilight Nightfall, a boy who had lost everything to the world, he remembered nothing of his former life.Stripped of purpose and will, he strayed on the path of despair. Yet, in his darkest moment, a reason to live revealed itself.Chosen as one of the sovereign system holders, Twilight was granted an opportunity to prove himself.With sufficient potential, he could earn the highest privileges, rise to the rank of seeker, and represent humanity in the Astral Realm—a game-like world filled with mythical races, limitless resources, and boundless opportunities.Follow Twilight as he ascends to the apex of the Astral Realm, dominating players and rivals alike while gradually piecing together the shattered fragments of his past life, becoming a legendary figure in all worlds.

The protagonist is an accidental time traveler - he didn't wait, didn't guess, only dreamed, but ended up in history, which he didn't pay much attention to. He was just lucky with his lineage.Ryo is a new member of the Nara clan, from the Uzumaki lineage on his father's side, and it so happened that he was born not at the beginning of the known plot, but more than three decades and two world wars later. Now he has to figure out how to get out of this situation however he can.