MTL - Mermaid Effect - Chapter 34

Dorian was out celebrating his college graduation when a car slammed into him, and darkness took hold.

220 years ago, in the legendary Dragon Demon War, Hero Azell ended the war by killing the evil Dragon Demon race’s King Atein. He was able to save the population, but as a consequence, he was cursed. While he was dying, the high magician suggested a gamble that might save his life.

After his parents died, Alex Roth had a plan: become a wizard. Through hard work, he was accepted into the world’s greatest university of wizardry—but fate had another plan.

On his eighteenth, he is marked as one of his kingdom’s five Heroes, chosen to fight the land’s great enemy. But his brand is 'The Fool', worst of the marks.

Rather than die or serve the other Heroes like Fools in the past, he packs up his little sister, his childhood friend and her cerberus, then flees for the university in hope of refuge, magic and to unravel the truth about his land’s evil.

There’s one small problem: The Mark tries to ruin magic while enhancing skills outside of divinity, combat and spellcraft.…

…that is, unless he can learn to exploit the hell out of it.

A teen is summoned to another world as the Hero. It turns out the Hero can power up women with his cum.