Gimai Seikatsu - Days With My Step Sister - Chapter 58 - 6

Anyone who could construct a stable Spell Model could become a Wizard — that was the Wizards’ ultimate secret! Having been given a new life as the son of an aristocrat and armed with a super quantum computer from his past life, Spell Models came as easily as breathing to Merlin. With this overwhelmingly huge advantage, would Merlin become the greatest Grand Wizard of all time?

- Description from Novelupdates

Alternate Title: The Snake Goes Ara AraBy cruel trick of the fates, intervention of stupid gods, or just the apathy of an uncaring universe I find myself woken up as Orochimaru just after he had possessed a woman for his new host. Now I need to find a way to turn this hoard of sycophants and psychos into something that will not only keep me from an early grave, but also how to change it to a force of change in this messed up world.

The mid-level boss of my company’s AAA-game.

One day, I woke up only find out that I’d become a Demon Lord, an individual responsible for protecting a dungeon. The world I’d been spirited away to was one filled with violence. Gigantic monsters wandered through it and competed with each other each and every day for the right to survive. I had no choice but to strengthen my dungeon’s defenses in hopes of living another day—or at least that was what I’d thought. For some odd reason, I instead ended up spending my days in relaxation and bliss.