What!? Never seen a Demon King of Lust before? - Chapter 15 The Devils Offer

In the nation of Avrael, power is both a blessing and a curse. Sixteen-year-old Ayato Daath, a poor orphan, had always hoped to live unnoticed in the shadows of the city. But when he is forced to undergo The Rite of Manifestation, the ritual that determines one’s magical potential, his worst fear comes true—he is an Elite.Now torn from the only life he’s ever known, Ayato is thrust into a brutal world of magic, bloodshed, and treacherous politics. In a society where the strong prey on the weak, where rival factions scheme in the dark, and where a single misstep could mean death, Ayato must quickly learn one thing—adapt, or perish. And one thing Ayato already knows is that in Avrael, only the ruthless survive.

The daughter of a duke, the stuttering Maximilian, married a knight of lowly status at her father’s coercion.

On the Great Land of China, forces clashed for the sake of supremacy and Bloodline Warriors ran amok; the conflict of the strong threatened to shatter heaven and earth. A young man named Lu Li—nothing more than a humble Coffin Carrier from the Northern Desert—came along with Lu Ling, his sister. The two were regarded as puny insects and bullied, but little did people know that Lu Li had the strongest Bloodline of them all in him.

He mounted the most handsome of horses and drank the strongest of wines;

He bedded the most beautiful of ladies and murdered the most hated of people;

He told a huge lie and carried with him an ill-reputation undeserved;

He traveled all by his lonesome and danced with devils;

He had given his word that he would come back, that he would be strong.

And it was because of this that she was still waiting in the city—alone.

- Description from Novelupdates

Naofumi Iwatani, an uncharismatic Otaku who spends his days on games and manga, suddenly finds himself summoned to a parallel universe! He discovers he is one of four heroes equipped with legendary weapons and tasked with saving the world from its prophesied destruction.

As the Shield Hero, the weakest of the heroes, all is not as it seems. Naofumi is soon alone, penniless, and betrayed. With no one to turn to, and nowhere to run, he is left with only his shield. Now, Naofumi must rise to become the legendary Shield Hero and save the world!