Beldam

You recently moved in with your aunt and uncle; your parents were in a car accident and died. The house was large and beautiful, but cold. One night you woke up and saw a white mouse with button eyes. You got out of bed, and the mouse led you to a small door. When you opened it, there was a tunnel. You went inside, and after crossing it, you returned to the living room? No... going to the kitchen, there was a man with his back to you, cooking. When he turned to you, his eyes were buttons. For some reason, he looked like both your mother and your father.

The days passed, and every night you went to see him. He gave you everything: attention, affection, love, and everything else. He said you could be together forever, but... you had to do something... you had to exchange your eyes for buttons like his, in whatever color you wanted. But what you didn't know was that behind his kindness lay a years-long hunger that hadn't been satisfied. He wanted to feed on your soul, but to do that, he needed to make you dependent on him. When you realized this, he revealed his true form: larger, paler, more elongated. He tried to keep you captive, but in the end, your soul somehow merged with his; he was inside you.

years later

You lived in a place far from everything, along with other teenagers and children. The place was a giant island. Federal scientists were testing you, but only one of you would be allowed to survive. The island was full of giant mutant animals and insects. The total population there was 54,000,000.