Caffeinated_fangirl
The seven, Nico, Thalia, Reyna, Will, Grover, Rachel, Clarisse, Chris, Connor, Travis, Calypso, and Katie go to Hogwarts - much to their dismay. They have to go to Hogwarts to protect the 'Golden trio' and to help them win the war. Harry starts to get jealous so that makes it a little bit harder to protect him. The demigods find some more of their friends there too!
I will be overlooking some of the deaths in the Harry Potter series for plot reasons
Lets just act like this is all happening in the same time line.