MTL - The Legendary Mechanic in Marvel Universe - Chapter 23 Parse Super Serum

Three years ago, to defeat the Demon God who was trying to destroy this world, thirteen Braves were summoned from another world. Each of them had varied ages and gender. Each of them was bestowed with cheat like powers not normal in this 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.

After dying from a gunshot, Reo meets the goddess Ophelia who offers him a rare chance. Instead of being reincarnated with no memory of his past, he can come back to a new world with the offer of receiving a legacy as well.Reo gets to choose from six legacy cards, each offering different powers. One card is blank—a risky option with slim chances of getting a good legacy from it. Ignoring the goddess’s warning, Reo picks the blank card and to both their surprise, he gets the SSS Rank Dark Dragon Legacy, a type of legacy so rare that only one human in Ophelia's world has ever had it.Reo is Reborn as Silva, he’s quickly labeled a failure by his noble family because he lacked magical ability at the moment , due to his legacy not yet awakened. His father, embarrassed and harsh, orders his death, but his mother begs for his life, sending him away to be raised by another family in a far-off town.Silva awakens his Dark Dragon Legacy, growing at a rate that was beyond normal, as he tried to understand the task the goddess had in mind for him, while still enjoying his new life.He also made out some time to pay his father back

The ordinary world is not ordinary, ordinary people are not ordinary, and safe places are not safe.

This is a story of a passer-by male protagonist who is entangled by various girls with strange hobbies or even non-human beings while surviving in the cracks and opening a harem.

- Description from novelbuddy