The supporting character's harem is very normal - Chapter 486: Am I a Villain Boss?

Ms Shen goes about her usual days while Mr Bo flirts with her relentlessly.

Year 2056, in a city in the Yuan Jiang Su Jin area. On top of a ruined, shattered six story residential apartment sits a teenager wearing a combat vest, militaristic trousers, and alloyed battle boots. On his back is a hexagonal shield and equipped is a blood-shadow battle knife. He sits there silently on the edge of the roof. At this time, the sparkling sky was shining and there was a refreshing breath within the air that blew towards him. However, there was only silence within the ruined, deserted city, with an occasional howl that makes your heart skip a beat.

- Description from novelupdates

Once upon a time, a boy was referred to as a “War Hero.”

In another world called Aletia, the boy who had saved the Lost Kingdom, conquered their neighbouring countries, and led to the rise of a grand empire decided to throw everything away, returning to the modern era at the cost of his memories.

As three years passed, the boy who was happily enjoying his daily life was once again called back to the other world.

However, what awaited him was the Aletia of 1000 years in the future.

As his past glories became a “myth,” the legend of the youth referred to as the, “Twin Black Hero King,” begins.

Ryuk’s life in the forsaken Grade E city was bleak, but it truly shattered when a Knull raid took his last family and left him for dead. On the brink of despair: [System Activation Complete.] [Congratulations, Host has awakened the Draconic Pets Evolution System!] [Welcome host, to the path of domination.] Thrust into Endearth, a shattered mirror of Earth teeming with mythical creatures—vampires, werewolves, cosmic gods—and the unstoppable Knulls, Ryuk sets out on a journey of relentless growth, vengeance, and discovery. But power comes with a price, and the dual nature of his gift could either save humanity or destroy everything. This is a story of evolution, redemption, and defiance. Join Ryuk as he rises from nothing, building unshakable bonds with allies and carving his path in a world where strength is the only currency.