My Leviathantale Soulmate AU

History

There was once a happily mated couple, a boss monster Selke and the other a human land walker who gave up his life on land to live in a Selke colony with his mate and four kids. Then something happened one fateful day when he was out fishing for his mate while they watched the kids. Some land walkers came demanding the youngest Layla because they found out that she was a mage. The mother whispered to the oldest “Mia take your sister and run, we will handle this ' and so she did. So she ran and ran and ran till she believed they were safe enough for her to switch to her seal form. She eventually ran into XGaster and he stole her pelt to keep her and Layla close. So Layla grew up with Cross, a thresher mer XGaster had so he could experiment on. After Mia was raped by her “soulmate”. They found out that he wasn't really her soulmate. He just wanted to create some hybrids to experiment on. Layla was also forcefully mated to Cross even though they aren't each other's soulmates but they eventually fell in love anyway sometime after.