Jelsa at Hogwarts

Hiccup, Rapunzel, Merida, JACK FROST, and Elsa are at Hogwarts. Anna, Kristoff, and Eugene( Flyn Rider) are there too. But there is dark magic stirring around Hogwarts. Who is it? Who will stop it? This is an AU story which means Alternate Universe where all the characters from different movies or books are all in the same world. Disclaimer: I do not own these characters. They are all Disney's and Dreamworks' characters.