"W-"
They hear a voice from the ocean
???: "Time's up, little siren..."
???: "There's only one thing I want from the likes of you. And your beloved has already refused me. So I offer again: give me the child, princess-"
"N-NO! I-I'm not pregnant-a-and even if I was I-I wouldn't give it to you-you'd just use it!"
???: "Oh? And what do you care what I use it for? After all, the ocean isn't your concern anymore, is it, little siren? You abandoned your home-what do you care what happens beneath it's waters?"
"I won't-I won't let anyone get hurt because of me. N-not as long as I can help it."
She laughs cruelly
???: "Oh, aren't you two foolish. This is a prophesy-you really thought you could just escape? The child is a being of the gods-it WILL emerge, whether you wish it too or not-surely you must've realized this, siren? And surely you must have noticed...the blue moon?"
She points up at the bright blue moon, and Delta's eyes widen
"N-no..."
???: "Oh...but this isn't just a child now, is it? As the prophesy says-it is a MONSTER. And it does not need anything but magical power to grow. It will be born-and she will die in the process."
"W-what...?"
???: "You really didn't know? Without another person for that baby to feed off of-a partner-it will drain you of all your magical lifeforce. Tonight, under the light of the blue moon, you will die."