Upgrade Specialist in Another World - Chapter 81: Frantically Rising in Power

Kyo Mazuru traveled to the world of Bleach and landed in the forest of Menos Grande at the beginning.Picking up a asauchi left over from Shinigami's death, and starting with a sword, he spent hundred years in the forest of Menos Grande to survive, slashing countless hollows, and his slashing skills reached the peak, until one day, he met a man who claimed to be Mr. Aizen Sōsuke!Mr. Aizen couldn't bear him to live alone in Hueco Mundo, so he invited him out of there and brought him to Soul Society!After that, Kyo Mazuru's Shinigami career began!

After dying in an oddly anticlimactic vending machine accident, Kazuki Ren is reincarnated in the demon realm—not as a hero, not as a villain, but as the only human male student enrolled at the mysterious Academy of Ruin, a school where all the professors are demon lords and all the students are powerful, beautiful she-demons.Ren is told he has one task: survive.But there’s a catch. The Academy’s darkest secret is about to awaken, and Ren holds a hidden power that could either destroy the demon world... or rule it.Now surrounded by seductive demons with hidden motives, eldritch tomes, forbidden dungeons, and twisted exams, Ren must master his ability—or be consumed.Magic, mystery, danger, and temptation await in this dark academia harem fantasy.

"What you do in life, Echoes in Eternity."

The System, who goes by the code name, Thirteen, defied the System God in order to give his previous Hosts’ the chance to change their Fates.

Unfortunately, he was killed by his Father, the System God, and was sent to the world of Pangea to struggle like the Cannon Fodders that he fought so hard to protect.

Armed with his knowledge as a System, Thirteen vowed to change not only his Fate, but the Fate of others whose destinies were tied up with him.

In a world torn by power and corruption, a fallen System will bring out a symphony of change, or lead it to its destruction.