The supporting character's harem is very normal - Chapter 108 New Talent – Adaptation

Bai Aoxue, the best mercenary in the 21st century, is accidentally sent back to the Chengxi Dynasty in Great Continent due to an explosion in her mission, and trapped in the first daughter of Prime Minister. After her rebirth, she is set up by her father to marry the 5th prince Jun Yeyan who wears a mask all day long.
In the face of bloodthirsty enemies, discord between brothers, collusion among courtiers and invasion of enemy state, can Bai and Jun resolve the crises? What will happen to their political marriage? How will the fierce battle for the throne end?
With many twists and turns, the book brings you to experience palace revolution, love and hatred thousands of years ago.

- Description from Novelupdates

In a world of brooding heroes and dark justice, one mercenary stands out—not for his skill, but for his relentless sarcasm and love for chaos. A self-proclaimed anti-hero, he finds himself working with the Titans, much to their frustration. While undeniably skilled in combat and nearly impossible to kill, his real talent lies in driving his teammates insane with endless jokes, fourth-wall breaks, and questionable decision-making. Whether it’s swapping Robin’s gadgets with toy versions, turning serious battles into slapstick comedy, or giving monologues mid-fight, he thrives on pushing everyone’s patience. But beneath the humor, there’s a sharp mind, a tragic past, and a surprising willingness to do what others can’t. While the Titans may roll their eyes at him, they also know that when things get truly dire, he’s the wildcard they need. Love him or hate him—he’s here to stay, and he’s having way too much fun.

Our straight (?) bottom woke up ten years into the future and found himself on the bed of his childhood friend… At the start, the bottom was shocked to his very bones, but he soon quickly accepted this premise and found the whole situation to be rather amusing. Precisely then, the bottom once again went back to his timeline — back to when he and the top were just platonic childhood friends.

Landmines include but are not limited to: Sweet & naive bottom, a president story, logic is dead, slow-progressing romance, the protagonist’s name has too many character strokes, the names are hard to pronounce, too many gay characters…

- Description from novelupdates

Dual cultivation and apocalypse—words that mix like oil and water. There's nothing charming about seducing feral women on the road.

However, when Kaze Lexicon, the emperor of the Immortal Plane, got transmigrated into the past, he refused to give up his debaucherous ways—apocalypse or otherwise.

Armed with the knowledge of the future and an encyclopedia of overpowered cultivation techniques, he immediately set forth to obtain resources and build a lavish settlement to live a comfortable life dual cultivating in the apocalypse.

However, while it's obscenely protected and powerful, he finds himself in another predicament. The cultivators farming humans for their war, and the desperate humans, become enemies far more dangerous than the zombies and monsters that afflict humanity.

Join Kaze as he rebuilds his reputation from a bullied weeb, obtains wealth, builds power, starts a faction, makes lemonade, trains his people, protects his past lovers, conquers settlements, and fights humans, monsters, and cultivators, all for the sake of two obscene goals: enjoying life and building an army of engineers to bring modern technology to the higher planes.