"I need something—a tool to bargain, a tool to place her under my will, or at least restrict her movements a bit. I can use brute force now, but that won't always hold."
"If she regains her power, I might not be able to hold her back… or worse, I could be defeated by her."
"Brute force isn't enough alone. I need to think," Ryuk mused to himself. That was when a notification flashed.
[CONTRACT GRIMOIRE: A page that makes everything written on it unbreakable. Breaking it will usually result in intense loss to whoever does so, sometimes even reaching as far as death!]
[Requirements: Only two people can use the contract page, and they must be equal in cultivation or at the same power level. If one power level is too high compared to the other, there's a chance that the contract will be broken with minimal consequences for the stronger one!]
[Price: A drop of life essence blood from both parties!]
The system suddenly came to Ryuk's aid as his eyes flashed, locking onto the notification.
"Genius. This is just what I need. With this contract, I can force her into a deal that she won't be able to break easily." Ryuk thought to himself, and in an instant, he spoke out loud.
Immediately, she suddenly materialized like a ghost by his side, a beaming smile on her face.
"You finally agreed?!" she asked, her excitement evident.
Ryuk rolled his eyes. "Only under one condition!"
He stretched out his hand, and a golden-colored paper appeared, inked in slashes of red and black.
The paper flashed in her eyes as she let out a surprised gasp.
"A Contract Grimoire!?"
"Yes, it's a Contract Grimoire. If you want me to get you out of this prison, then you must agree to my deal and sign the paper!" Ryuk said as she looked doubtfully at the page for a while before eventually nodding.
"What are your terms?" she asked.
"Simple. You listen to my will for as long as we are on Endearth. That's the only way I can make sure I don't bring back a threat that will bring death to my people."
"In exchange?" she asked.
"I'll bring you with me back to Endearth," Ryuk stated, making it as clear as possible.
But he was shocked speechless when he saw her suddenly bite her finger. Then, she flicked her hand toward the book, a blue drop of blood splashing onto it.
The page lit up with a bright golden light.
A drop of blood left Ryuk's finger as well, drifting into the book, which vibrated with a brilliant dark and golden light before it disappeared into the empty void.
"You… agreed so easily? I thought you would try and argue the terms a bit?" Ryuk asked in shock, but she only chuckled.
"Oh, you're very naive. Don't you know a Contract Grimoire can be broken? You might not know, but compared to my true level of power, my current power is like a drop in an ocean and just about yours," she said with a smirk.
"Once I get back to your world, I will find a way to increase my power level. No doubt, I'll become vastly stronger than you are. Then, I can simply reach into the contract core, find the page, and break the contract due to our massive power difference."
"You're from a lower world, aren't you? That means you're most likely already nearing your full potential. My guess?"
"A couple of months from now, and your stupid contract will be broken by me. And you can't go back on it anymore."
"Once I break your contract, I'll finally regain my freedom. And then, you will be the one under my will."
She smirked as Ryuk furrowed his eyebrows.
"But of course, I understand you're just worried about your world."
"Still, a lower world dreaming of standing against the Knulls is pure fantasy."
"I don't intend to harm your people. They would all be turned to ashes by the Knulls anyway."
"Once I regain my true power, I will leave Endearth for an upper world."
She giggled loudly, her laughter ringing through the void as Ryuk looked at her for a while, his expression showing surprise. This only made her giggle more.
But Ryuk had only smiled in his heart.
'Already near my full potential?' he thought to himself as he laughed darkly.
"My potential is an abyss that will most likely never get filled until my own death. You have no idea what you just got yourself into…"
[Well now, Host has a new servant.] The system's voice rang in his mind as Ryuk grinned.
He had expected her to negotiate the terms of the contract—maybe something like she wouldn't be able to harm an Endearthian. That would have been the expected move.
But Ryuk had devised something bigger so they could negotiate about it until they reached a level of agreement.
Who would have thought she would instantly agree to become a slave to his will, simply because she believed that in a couple of months, she would regain her power and become stronger than he was—thus breaking the contract?
Ryuk already knew the contract could be broken if he allowed her to grow strong enough. So, there was no way he would let himself stall behind her for long.
And her guess of him being close to his potential due to being from Endearth was just ignorance.
Ryuk might call his world Endearth, but he knew well that he was not an Endearthian.
He was an hybrid of two of the most powerful races in the universe.
His potential was an abyss, even he himself wasn't sure if he would ever fill it until he died.
She had just essentially signed herself to his will for as long as he lived.
"Well then, what are you waiting for? Let's get going already!" she said, dropping to one knee, pressing both palms onto the ground.
Soon, a runic portal appeared beneath her. Ryuk slowly stepped forward.
'Finally. It's time to go back home!'
'I wonder how things are back in the real world.'