Reincarnated Lord: I can upgrade everything! - Chapter 15: Tier Upgrade Quest

Renji Kurozawa was just another nobody—until he died and was reincarnated in a world of swords and magic. Summoned alongside other “Chosen Heroes,” he hoped for a second chance at life.But his gift was different. “Death Claim”—the power to steal abilities from those he kills.Betrayed by his allies and left for dead, Renji embraces his dark power. With every enemy he slays, he grows stronger, turning from a forgotten outcast into the most feared force in the kingdom.Now, hunted as a villain and pursued by gods, Renji must carve his own path—one kill at a time.If fate wants a monster, he’ll give them one.

What happens when a man gets transported into a foreign world filled with magic?

What would happen, if one day fantasy collides with reality?

- Description from Novelupdates

Kyoukai Senjou no Horizon chronicles the story of a futuristic civilization returned to Earth after constant warfare hindered them from traveling beyond the post-Apocalyptic Earth. At this stage, a small archipelago called the Divine States were the only hospitable land on Earth. In order to regain the space-faring technology they had lost after many years of war, they decided to recreate history with a book called the Testament as a guide.

It is the year 1648 in the Testament Era. Toori Aoi, Chancellor and Student Council President of the only academy on the airborne city-ship Musashi, faces the ten-year anniversary of the death of his childhood friend Horizon Ariadust in an accident. As he prepares to celebrate the occasion by proposing to P-01s (an automaton who looks exactly like Horizon) he discovers that his suspicion about P-01s’ appearance actually has a basis in truth; P-01s is in fact Horizon Ariadust, reborn into a robotic body. In addition to this, Horizon’s emotions had been stripped away and are now stored in eight powerful weapons called the Mortal Sin Armaments; which are now in the possession of key people in various established countries in the Divine States.

To retrieve the emotions of Horizon Ariadust, Toori Aoi along with his friends and allies begins a crusade against different obstacles as key events in history are recreated in a futuristic manner.