My Runes Can Be Upgraded - Chapter 1149 - : Stayed 2

Rex was an ordinary salaryman, resigned to a dull life of monotony in a towering megacity. But his world shatters when he’s conscripted by Nexum Dynamics, a ruthless megacorporation, and thrust into a brutal war for a barren, alien world. The planet holds unimaginable riches, but it’s also swarming with the Krhyssari, an insectoid race that dominates the surface with their hive-mind precision and relentless aggression. Amid the carnage, Rex had an extraordinary encounter with Cleo, an ancient AI, a survivor of a long-extinct civilization. Cleo isn’t just an artificial intelligence; she’s a consciousness imbued with memories of her people’s interstellar empire and equipped with advanced bio-nanotechnology. Offering Rex a new purpose and unmatched power, she transforms his fragile human body into a hybrid of living metal and flesh, making him the ultimate weapon. But Cleo is more than a tool of war. As she journeys alongside Rex, her cold, logical algorithms evolve, shaped by his humanity. Together, they form a bond that transcends the boundaries of man and machine, discovering love in the midst of chaos. As Rex and Cleo fight for survival, they uncover a shared ambition, to rise as intergalactic overlords, uniting or conquering the galaxy.

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates

The protagonist, having degenerated into a “loser” after being unable to find employment, gets caught up in someone else’s attempt to commit suicide-by-train and ends up traveling to another world. The numerous cheat powers he demands from God are all granted to him. But contrary to expectations, these powers bring about disastrous consequences for the protagonist.

Having reincarnated into another world, the optimistic protagonist (Yuuri) starts his(her) heart-warming training days with his(her) teacher.