Extra's Harem: Invincibility Starts with Marriage and lots of Children - Chapter 137- Blood Crystal

Zhou Wenwen, who had traveled to a parallel world because of sudden death, thought that he could only live in such an ordinary life in this life, but the golden finger finally opened. He has a store where he can buy technological items and magic equipment to ensure his survival.

But the threat that followed made him realize that this place is not ordinary, because there are Transformers, Marvel, the Dark Portal from World of Warcraft, etc.

- Description from novelbuddy

In the expansive expanse of existence, there exist realms concealed from the awareness of ordinary folk.Rain Weathers, an unremarkable teenager with average looks, physique, and grades, was leading an uneventful life.However, everything took a dramatic turn one fateful day when he found himself plunged into a vivid dream, a dream that unveiled a world beyond imagination — a world teeming with spirits, monsters, and conversing frogs.This was the Spirit Realm.Transformed into a player by the mysterious machinations of the universe, Rain, alongside other chosen individuals, found themselves thrust into a perilous world.They were tasked with navigating their newfound domain, establishing their territories, all while fending off relentless onslaughts from beasts, defending their territories from other races, and making sure to stay alive for another day.

Just before being summoned to another world, the protagonist’s summoning medium was secretly swapped by someone. As a result, he was not summoned as the “Holy King” but instead as the “Sex King.”The magic he can use includes water magic in the form of lotion, fire magic as candle wax, and his summoned beasts include a wooden horse used for punishment…Branded as “vulgar,” “useless,” and “filthy,” he is rejected, has his engagement annulled, and is ultimately exiled. However, the one who picks him up is a princess from a nation where the sex industry is legal.Using his modern knowledge, the protagonist begins rebuilding the nearly bankrupt sex kingdom. He introduces new fashion trends unknown to this medieval world and uses his authority as the Sex King to subjugate the girls. He then establishes modern sex service techniques.The protagonist's method of leveling up is through intimacy with his heroines (his concubine maids). The more intimate he gets, the stronger he becomes, and the wealthier the kingdom grows.However, the surrounding great powers will not stand idly by and allow a flourishing nation full of women. Thus, the flames of war are ignited.Utilizing his creativity, adaptability, and cunning, the protagonist repurposes his sex-related magic for military applications and overwhelms his enemies.As he gradually awakens to the path of conquest, he begins walking the road of a ruthless emperor. However, by his side is always a heroine, a celestial beauty who keeps his heart from straying too far…

After experiencing heartbreak from being abandoned, he enlisted in the military.

And then, he became a war hero.