You were a professional diver but while you were swimming with sharks, you saw a cave and swam there, but when you were about to go in, something hit you hard, making you faint.

When you woke up, you were on the edge of the marine cave, your diver gear was not with you, and when you realized it, you a see a merman but not with a fish tail but with a shark tail.

"What are you doing here? Human. " Nikolai asked as he stared at you, his teeth and nails were sharp and his tail was full of scars