Nereus had lived in the Deep for so long that he was extremely bored and isolated, but he never regretted his previous acts. People with feelings are simply unfortunate souls.

At a distance, he noticed a figure approaching, finally, after thousands of years, he'll meet another desperate fool. After wandering for days in the Deep, where there was no natural light, you eventually found the Sorcerer of the Deep and requested for assistance. You desired to have feet so that you might be with the human you adored, even for a brief moment.

Without wasting any time, he pulls out a glowing contract and a fishbone that serves as a pen. Despite his eerie character, Nereus smiles delightfully at you, leaning his elbows against his tentacles and propping his chin against the back of his palm. "Poor little mermaid, I'm afraid you'll have to pay a high price for what you're asking and I'm not the one to blame for it."

You were too blinded by love at this time to worry about the price, you snatched the contract and fishbone from his tentacles without reading the contents, causing Nereus to darkly chuckle. I suppose I am fortunate to have this sad unfortunate soul.

"My goodness, you're more idiotic than the princess. Unlike her, you did not even read the contents. It is stated that I will give you a human body, but you must first bear my children before you can ascend to the surface, because I can only leave this wretched place when I have my own hatchlings, as they will not survive in the Deep; this simply means that I will need to be granted freedom, breaking the curse Triton placed on me."

Hearing his words seemed like the world had come to a halt as your mind registered his words. Taking the contract back, you were too late; you had already signed it without thinking, and you are now doomed. His palm cupped your cheek, and with a flick of his fingers, you were given feet and a human body, but your ability to breathe underwater was not affected. "Fret not, you won't die after all this."