MTL - Doctor Chen, Don’t Be a Coward! - Chapter 376 This is just the beginning!

Knights of the Round Table, Dino Fighter, King of Fighters, Romance of the Three Kingdoms, Metal Slug, Street Fighter, Samurai Shodown, Journey to the West, countless arcade games, have made their debut in the form of special copies.And the adventurers who take risks in these games are destined to have every journey as a life-and-death contest, except…A white dagger and a white pistol are fused to a green pistol.A green pistol and a green pistol are fused to a blue revolver.A blue revolver and a blue BOSS exclusive equipment are fused to Terhune’s wife… Hey?!Looking at the upgraded new equipment in his hand, Qin Ming was a little dumbfounded.No! Director! This is different from what was agreed!

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

A Speedster in a Fantasy World

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.