This Life, I Will Be the Protagonist - Chapter 294: The Power of Mahjong, Three Levels!

A surgeon accidentally got the blessings of a system, shocked the medical industry, and rejuvenated countless people.

- Description from Novelupdates

Traveling through different worlds – this is unscientific!

Get cheats – it’s science!

…

This is a simple story. An ordinary person lives in a different world, farming and raising flowers, studying unscientific science in his free time.

until the end.

- Description from novelbuddy

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.

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.