HP: The Arcane Thief - Chapter 4: The New Diagon Alley

The world is big, but I am the only one who is orthodox.Sweeping the world's immortal sects with the power of the Celestial Dynasty.A strong man who practiced the 'Way of the Emperor' came to a world full of immortal sects, and a secular dynasty that was despised by the practitioners gradually came to be on an equal footing with all the top immortal sects.The law of the dynasty is that everything in the world is the king's land, and the shores of the land are the king's ministers! There is only one orthodoxy in the world, and all immortal sects are illegal organizations!

“Jiang Yu transmigrates into a novel and becomes a side character in the book.

In her last life, she was miserable and ordinary. This time, she got into the fashion and was reborn in another world. She was still the same person… even with the same body and face. What was the point of reincarnation? A childhood companion? He always pulled her hair and made troubles for her? A handsome boy? The boy never looked at her and was 15 years older than her! A prestigious teacher? The teacher spent his days eating and drinking, coaxed, played tricks, and controlled others… Too scary and better run away? No no no, such a challenging life was bound to be wonderful! Now let me take you back to the 70s and live a fast life!

- Description from Novelupdates

An ordinary young man reincarnates as Adrian, the eldest son of a once-prominent noble family now living out in boonies of the kingdom. Watch as Adrian embarks on a tantalizing journey, to support his graceful and caring mother and feisty older sister, as a man should, with his seduction system.