My concept for Ramona's 8th Evil Ex: Felix Faustus.
You know how it is. You meet a goofy hipster guy. You visit his place, and he's got a couple of cats. Sweet, right? Taken in by his unassuming, caring nature, you start dating him.
Next thing you know, he's got another cat. Then another. Then even more. His apartment becomes cluttered with cat toys and litter boxes. It smells like Meow Mix and pee. Everything in it is covered in a fine layer of fur.
The cats have begun to warp his mind, and next thing you know, he's sold his soul to the Devil for mind control powers over his now-formidable feline army. You bolt. He doesn't take it very well and vows eternal revenge.
These things happen.