That Time an American was Reincarnated into Another World - Chapter 21: Enlightenment

A novel revolving around being transported to another world with an op system. The mc spends his day chasing skirts and doing missions to level up. A standard journey to the top with lots of girls from various animes and games with a twist of that gaming feel (hunting mobs, doing missions).

- Description from novelupdates

Masterpieces such as 'The Divine Comedy', 'The Theory of Evolution', 'Encyclopaedia Britannica', 'The Theory of Relativity'...Born in the history of human civilization, possess mysterious and magical powers in another world!Original sin, biological evolution, mastery of all arts...By reading the secret tomes, one can gain a variety of powers!The only trouble for the people of the other world is that they find it difficult to understand the texts from Earth.At this time, there comes a librarian from Earth...

Leguna. An orphan. His life changed dramatically the day the thieves’ guild happened to select him for training and development. He would go on to become lifelong friends with a loyal mercenary, the partner of a beautiful magus who was cold as ice, the savior of a mysterious disfigured dark-elf girl with a talent for the Breath, and the unlikely caregiver for a feisty young maiden. And yet, who would be with him to the very end?

“I was born as a princess in the most powerful lineage in the world… but that lineage is now on the verge of collapse.”In a kingdom where strength is everything, royal blood has long ceased to produce true powerhouses. Sects and clans are just waiting for our family to show weakness so they can tear us apart.But this lineage is not dead yet.He is still here.A being feared even by the strongest cultivators.The only reason this kingdom still stands.And me?If I want to survive in a world where only power matters… I must become a monster feared by all.