With all the other people we've faced who wanted to hurt us, it was easy to understand...

[Varian wanted revenge because he felt they failed him and his father. Zhan Tiri wanted to destroy Corona because it was the kingdom Demanitus loved so much. Cass felt hurt and betrayed and was manipulated into thinking Rapunzel was the source of it all. They're not good reasons at all to do what they did, but... at least they were reasons.]

But this... it feels like whoever's behind this is doing it because they think it's fun, or something.