There Was No Secret Organization to Fight with the World's Darkness so I Made One (In Exasperation) - Chapter 1 part1

The story of otaku building a harem! School flower, loli, wife, mother and daughter, mature woman, teacher, nurse, queen, all kinds of beauties, three steps to push a girl, five steps to a group, harem group, infinite warmth, so cool that you always need to prepare a tissue for easy reading !

- Description from novelbuddy

...[Inside an underground basement]“You are going to die for nothing, hahahaha,” the old man's voice thundered through the room, sending chills down my spine.Step.With a swift and ruthless motion, he lunged forward, his sword slicing through the air and slashing my throat, crimson droplets staining the darkness.“We'll see,” I whispered defiantly, my final words escaping as a mere breath against the impending darkness.Slowly, inexorably, my consciousness slipped away, and I descended into a deep, unfathomable slumber.“Huh!?” My eyes fluttered open, and I found myself seated in a bustling tavern, the air thick with laughter and the clinking of glasses.In front of me stood a captivating lady, her beauty juxtaposed with an angry furrow upon her brow, threatening to shatter the harmony of the jovial scene.“Don't follow me around!” Her words pierced the air like shards of ice, the intensity of her emotions palpable as she cast a resentful glare in my direction, before swiftly departing from the tavern....Am I trapped within the confines of a game? The fragments of my shattered common sense scattered before me, leaving me to question the very fabric of my reality.

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