City of Sin (Yanyu Jiangnan) - Vol 1 Chapter 6: Family

This is the story of a boy who lived a secluded life in the mountains, tending his farm, rearing his fish, and dreaming his dreams. Eh? Did I suddenly conquer all worlds and become the big boss? Or am I still in a dream?

- Description from Novelupdates

When the enigmatic and overpowered Kieran Drayke awakens in a foreign magical world after a sudden transmigration, he brings along a system unlike any this realm has ever known. The “Sovereign Architect System” doesn’t just make him invincible—it gives him the tools to build something far greater.But Kieran isn’t interested in world domination. At least, not in the usual way.Disillusioned by the world's surface-level glimmer and the rot beneath it, Kieran sets his sights on the forsaken—those discarded by society, lost in the shadows of nobility and corruption. From slums, war zones, and forgotten ruins, he gathers orphan girls of various races—elves, beastkin, humans, and more—each with untapped potential and pain behind their eyes.He trains them in secret. Guides them. Empowers them. Not as soldiers, but as a family. A hidden organization that operates behind the curtains, shaping the world while appearing as ordinary students at the prestigious Aetherion Magic Academy.Kieran himself? Just a carefree, slightly lazy transfer student with a penchant for sweets, sarcasm, and sneaking naps between classes—on the surface, at least.With a slow-burning plot that weaves magical worldbuilding, deep friendships, training arcs, casual comedy, and a cast of unforgettable girls who grow into queens of the unseen, Chronicles of the Hidden Crown explores what happens when an OP MC doesn’t conquer the world with brute force…But builds a legacy from its forgotten pieces.No betrayal. No forced drama. Just the steady rise of a secret kingdom in the shadows of a crumbling empire.

Yang Feng somehow transmigrated into a different world and received a legacy of an ‘ancient high tech’ family, which does not directly raise his power, but gives him the technology to build things which are way more advanced than the seemingly medieval world.