Demigods At Hogwarts

The second giant war is over and everything is back to normal (sort of? ). The older campers are all living at Camp year round, mostly. They are allowed to visit the mortal world whenever they want. They are having the time of their life. Atleast until a minor goddess shows up offering a Quest. She introduced another group of supernatural people threatening to infiltrate Camp, if denied.

Voldemort is dead, or atleast that's the belief. They don't know for sure. Neville Longbottom had killed Nagini. Harry had won the duel between him and Voldemort. Sure he had disintegrated, but were they sure he was dead. He might've had another horcrux. Knowing he was weak he might've fled.
And now this new group of people arrives. They don't seem like magicians even though could perform magic. One of them was waaaay more better than any of the Hogwarts students. They are almost sure that the pale boy is a Death Eater. But they can't do anything Dumbledore isn't listening to them, not even to Harry. And Snape seems overly interested and friendly with them.