Youkoso Jitsuryoku Shijou Shugi no Kyoushitsu e - Volume 15, Chapter 3: A Fight Against Solitude, Part 1

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?

Childhood sweethearts.
The most popular person in school is my childhood sweetheart.

- Description from Novelupdates

[You have been chosen as a Lord of the Intergalactic Lord Project.] [Your reward: A floating island to call your own.] [Your mission: Build your kingdom, summon legendary allies, and dominate the worlds!] [Your advantage: An SSS-grade Ultimate Gacha System.] Atlas Blackthorn, the newly chosen Lord of a floating island, wields the power to summon legendary warriors, powerful artifacts, and, of course, waifus. With boundless ambition and the Ultimate Gacha System at his side, Atlas sets out to become the strongest Lord in all worlds. How far will his ambition take him?