The supporting character's harem is very normal - Chapter 212 It’s interesting, but also very stimulating.

Son of a bitch! I just finished this godawful fantasy novel, and now I'm knee-deep in it – as David, the disgraced son of the Solarian Empire's top general! Talk about some twisted cosmic joke. But hold on a damn minute... maybe this isn't all bad. Armed with the knowledge of that trashy plot, I can become the ultimate shadow player, an overlord perhaps. Screw the damsel-in-distress harem too – it's time to pull the strings and become the real power behind the throne. This isekai might be a steaming pile, but I'm rewriting the ending with a little more... Debauchery (wink wink).

This is a story about exploring technology in a wizarding world.Probability, electromagnetic induction, nuclear physics and theory of relativity—all of this can be mastered through scientific exploration and learning.Richard had always thought so… until he transmigrates to a world similar to the Middle Ages and becomes a prince. In this world of wizard and magic, he embarks on a journey to explain magic with science. One day, a dragon takes him away.“This is not in line with aerodynamics? It does not satisfy the Kutta condition, Circulation Theory of Lift and Bernoulli's principle either? How can it fly? Is there a special power source in its body?” Richard could not help saying as he glances down at the huge dragon he was riding on. “Well, I need to research this.”“By the way, you said you kidnapped me to find a playmate for your daughter. That doesn't sound like a good reason, right?”“Roar!” the dragon hollers furiously and waves its wings, soaring into the sky.Will Richard be able to continue on his journey of exploration and unravel the mystery of the wizarding world?

Childhood sweethearts.
The most popular person in school is my childhood sweetheart.

- Description from Novelupdates

Everything functions in a cycle, be it an ant, bird, lion, human, or even a celestial body.This cycle initiates with one's birth and governs one's end, yet there exists the potential to surpass it.Among the billions of planets floating in the cosmos, destined to merely occupy a void, some have the capacity to ascend, reaching new dimensions, standing shoulder to shoulder with realms like Heaven and Hell.---Vlad, a young man, found himself ill-fitted in a world that scarcely offered him any luck, weighed down by a mysterious secret that initially seemed more of a burden than a boon.Yet, the powers he had dismissed as trivial eventually became his most formidable strength when the apocalypse broke, unleashing literal pandemonium as angels and demons walk among the human race.