MTL - Shocking the Whole Internet! You Are Not a Psychologist at All! - Chapter 20 might as well make it clear

I can be the main character even though I’m not a hunter. Kang Moo-hyuk succeeded in all the raids with his genius and rose to the position of Strategic Team Leader despite not being a hunter.But one day, he got diagnosed with a terminal illness called “mana addiction”, and even got involved in a power struggle within the guild. With only a few days left to live, he decided to do everything he every wanted and set his passions ablaze. And he chose the tier 1 “Taesung Guild” to do so.But how can Kang Moo-hyuk grow the guild with Joo Se-ah when the rest of its members are amateurs?

The previous life is nothing but a joke. Being used completely then abandoned mercilessly. How can I be this stupid to not even notice such an obvious scam? Fortunately, I can have a second chance with my rebirth. Sister, Brother Yi and whoever mistreated me in my previous life, are you ready for my revenge and the counterattack of a princess?

A life filled with regrets.Once he realized his faults and decided to lead a new life, it was too late.His family was already gone.He had borne through each day with pure rage.Finally at the end of his misery, his wish reached the heavens—an unforgiven one.He goes against fate to raise his sword.

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.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates