MTL - House Dad’s Literary Life - Chapter 1243 Murphy (2/3) with "magnificent ambition"

A world where God will grant abilities called Skills to those who come of age. The protagonist, bestowed with two skills, uses them and rises to an existence called a hero.

In the middle of a deserted island, a small boy wakes up with two sets of memories: one from his few years of life and the other from a man who lived to adulthood and achieved great things. When he least expected it, a powerful master appeared on the island and took him in as a disciple, revealing a shocking fact: magic exists in that world, and, thanks to it, humanity managed to conquer the galaxy.

In the post-apocalyptic age, men were damned.