Prologue: Fifty Thousand Hours
A message window suddenly appeared before his eyes.
50,000 Hours
Twenty-four hours in a day. Eight thousand seven hundred sixty hours in a year.
Was that even possible? Only if you did almost nothing but game from the moment you woke up until you collapsed into bed.
Kang Dong-hyun had started gaming in elementary school. Now twenty-five, a high school graduate with nowhere in particular to be, he found himself staring at the strange message window floating in front of him. He didn't work anyway, so he'd been grinding away at his games when the bizarre window suddenly materialized before his eyes.
Ah... so I'm finally losing my mind. Can't say I haven't earned it... this miserable excuse for a life...
That was the first thought that crossed Dong-hyun's mind as he looked at the message.
In that instant, the window split down the middle, and dark flames like the fires of hell spilled outward. Dong-hyun toppled backward out of his computer chair before he even knew what was happening.
The flames spread wider and wider, and from within them, a finger pushed through. It pried the rift apart as if tearing open a seam in the world, and from the other side, a human figure began to take shape.
An angel?
No one could have blamed him for thinking it — if not for the horns crowning her head and the wicked, seductive tail swaying behind her.
A demon?
But her face was far too lovely, far too gentle for that. And the black dress she wore was so revealing it barely deserved the name. Her beauty was so staggering that Dong-hyun sat frozen, as if she'd put a spell on him.
Once her form had fully taken shape, Serién slowly climbed atop the fallen Dong-hyun.

"You're Kang Dong-hyun, right?"
"Huh? Ah... yes!"
A voice so beautiful it could enchant anyone spilled from Serién's lips.
"How... how does someone your age even have fifty thousand hours of playtime?"
She asked the absurd question while still straddling him.
"Well... I mean... I pretty much just ate and played games."
"Hmm... I see..."
She accepted the answer far too easily.
"My name is Serién. I look forward to working with you."
"Working on what?"
Dong-hyun shot back, since she hadn't actually said what she wanted from him.
"Ah... right. So, here's the thing. Someone who has this much fun playing games... you'd be pretty good at them, right?"
"I... guess so?"
Dong-hyun's League of Legends rank was Challenger. In Valorant, Immortal. The reason he could pick up any game and play it without stopping was because he actually had the skill to back it up. Strategy games, MOBAs, every kind of RPG, shooters, puzzles, roguelikes, action, racing — he had genuine talent across the entire spectrum.
The only reason he hadn't gone pro was that he hadn't chosen to. Offers had come in from all over. Part of it was that Dong-hyun didn't want to make money off the thing he loved. But the bigger reason was that he wasn't exactly hurting for cash.
Dong-hyun was a third-generation chaebol. A conglomerate heir, technically — except he was nowhere near the line of succession. In other words, he was the hidden son of a mistress. Money was rotting away in piles anyway, and the legitimate children were more than happy to see him wasting his life as a shut-in. They'd applaud him for it. In a way, it was a mutually beneficial arrangement.
"If you grant my request, I'll give you an incredible power."
"Like what?"
When she'd first appeared, he'd wondered if any of this was even real. But after talking with her, Dong-hyun no longer found Serién frightening.
"Incredible wealth?"
"Money? I don't know about that..."
Dong-hyun could have as much money as he wanted, whenever he wanted.
"You don't want money? Then... power?"
"Sounds like nothing but a hassle..."
"What?"
Serién was thrown by the man sitting in front of her.
"Then how about strength? The kind of power no one in the world could ever ignore."
"And what would I even use power like that for?"
"Oh, for crying out loud! You're a man — how can you have so little ambition?! Huh?! Fine. What do you actually want? Name a real wish and I'll grant it on the spot. This is a high-ranking demon talking, so there is absolutely no lying."
Serién's words came out sharp, clearly irritated by Dong-hyun's attitude.
"What I want...? Hmm... you?"
The instant the words left Dong-hyun's mouth, something dark and wet spilled from both his lips and Serién's, reaching toward each other.
"N-no!!! Absolutely not!!!"
Serién cried out in shock, waving her hands through the black smoke — or was it liquid? — but it didn't scatter even when it touched her fingers. It kept pouring out until their essences finally connected.
Dong-hyun suddenly felt his heart pound so hard he clutched his chest with both hands. Serién felt the same thing.
A mark has been carved into the deepest part of both souls.
The contract is sealed.
There is no undoing what has been done.
A contract of the dark gods had been sealed — a mark carved into the deepest part of each of their souls.