MTL - When Heartthrob Omega Wears Into the Present World - Chapter 10 Inhalation of pheromone sequelae?

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

“I’ve been possessed into the controversial makjang drama ‘Gwangin’ (The Lunatic). Of all roles, I’m the omega secretary to an alpha with omega-phobia. It’s hard enough hiding my identity, but I’m also in charge of all sorts of annoying tasks: managing the protagonist’s diet, wardrobe, and house; coaxing and soothing the beta he loves. My goal is to survive until the ending where the protagonist meets the strange beta who thinks even his obsession is love, leading to a happy ending… I think I smell an omega somewhere.’ ‘That’s… impossible.’ If I speak carelessly, I die. If I mess up my work, I die. If I run away, I die. And if the fact that I’m an omega is revealed… I really die. ‘Right. It shouldn’t be possible, but that’s why I feel so f*cking awful, Secretary Kim.’ Will I be able to make it back alive…?”

Jacob Steve, an Old Man, died at 116 after living a whole life.

But Jacob always had a dark side, which he always suppressed and hid from others.
However, in the later years of his life, when death was inevitable, he understood there wasn't any point in having wealth, knowledge, or desires if you couldn't have a life to enjoy them.

He became obsessed with fabled immortality and devoted his reaming life to extending his fleeting lifespan, but just like any other failed.

However, he mysteriously got another chance at life and found a way that led to fabled immortality.
But he was also forewarned that the way led to it was filled with blood and darkness!

In the end, Jacob chose it anyway with no way of going back, and it was also the start of his suffering and his icky, brutal journey toward the 'Immortality' he wanted so badly!

But things seem to be different from the history that he knows.In this strange land, ancient legends walk the earth. Here Witches, Manticores, Vampires, Werewolves, Sirens, Dragons and Krakens are all terrifyingly real.As if that weren’t enough, this is also the age of legendary rulers—Baldwin, Saladin, and Richard the Lionheart —each destined to shape history in a new wave of Crusades.Amidst bloodshed and glory, Lothar must use his only advantage—his Gacha System—to build his territory, summon legendary units, and carve out his legacy in a world where ambition reigns and power speaks.