Virtual World: Close Combat Mage - Chapter 28 - Fireball joins a guild?

Zarah is nothing but a lowly runt in Howl Creek who is bullied relentlessly. She wants nothing more than to leave the oppressive pack. When it is revealed who her mate is—none other than her greatest bully, Alpha Damon—she is humiliated and rejected.She leaves for the human sector and lives her life with her son, only for the past to come knocking. Alpha Damon is back, and he wants his son.

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.

Yo, Hi! I’m Frank, I made a deal with a demon to pay me some money for receiving a guest for a few days every week.
I had no idea about what I have done.
On May 1st, Conan ‘the God of Death’ came to my house. I was forced to let him in and we get involved in a criminal case.
On May 8th, Bruce Wayne ‘Batman’ came to me. I was forced to follow him to fight crime.
On May 16th, Hannibal Lecter, The Silence of the Lambs, came to my home. I can only say that I really can’t stand my guests.

- Description from Novelupdates

The most successful businessman of his time, who started from being a homeless orphan, died indignantly because of being plotted against by his most trusted aid, his own brother.