MTL - This Uchiha is Too Cautious - ~ Just a few questions about book friends

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.

A mysterious and strange world, a human civilization lacking power, and a horrible and turbulent world of human life, Luo Kai survived humblely as a prisoner. Pain and suffering honed his will. War and killing promoted his growth. He suddenly looked back. Is already one of the most powerful beings in this world.

- Description from novelbuddy

One week. If you survive, you choose a Cosmic Power... you survive. Jace isn’t one to give up. Not when his sister dies. Not when he loses his legs. And definitely not when The Cosmic System takes over Earth. With nothing more than his street smarts, the clothes on his back, and a river otter companion; he must survive a planet full of vicious predators that see him as an easy meal. If he can survive? He gets to choose a Cosmic Power and a Class. A path to ascension. A way to bring his sister back.