Toaru Majutsu no Index: New Testament - Volume 16, Epilogue: A Model Answer that Exceeds Disaster - Nightmare_by_Lost_Boy.

When an S-class elite assassin-raised captain of a special ops suicide squad comes home from a high-stakes Africa mission, he finds himself offered something that could potentially set him up for life- a curious assignment that he could use to finally exit his days of war and slaughter.

In a world where strength reigns supreme and only the strong are revered, conflict and injuries are commonplace.

In the near future, a space channel connecting the other world suddenly appeared on Blue Star, and a large number of other world monsters poured into the homeland where human beings depended for survival.

Human civilization has shrunk sharply and had to hide in the base city to survive.

Only warriors can lead human beings to open up living space and regain lost land.

However, martial arts requires talent, and not everyone can become a martial artist.

People with outstanding martial arts talent can not only advance quickly and break through limits, but also optimize their exercises and benefit future generations, and are admired by all mankind.

By chance, Lu Heng discovered that his martial arts talent could continue to evolve…

- Description from novelbuddy

In the year 2025, humans awakened with the ability to summon mighty beasts—capable of destroying terrains, breaking the laws of physics, and creating wonders limited only by one's imagination.But before these blessings came a curse.An alien face appeared from nowhere and threatened all life on the planet, leading to the greatest war in human history.In the aftermath, the human race and the alien race were forced into a shaky treaty that could be broken at any time.Years later, tests for summoning abilities began for the next generation. Those who awakened low-grade summoning would be thrown to the gutters, while those who awakened higher got to join great factions after graduating from the academy.Kairos Veyl, the blank, calculating student, pulled his hand from the massive crystal pillar and stared at the large beast before him.“This kid—he just got a LEGENDARY SUMMON.”A legendary summon? The greatest class of summoning. However, with this class came a risk one would have never guessed.