The Triwizard Pact

Gellert Grindelwald, a feared and somewhat hated student among most of his fellow students. An intelligent rising talent to his teachers. These dangerous qualities led him to become the Drumstrang champion in the Triwizard Tournament.
He came to Hogwarts at the cost of being cut off by his devoted followers at Drumstrang. Surrounded for months by students who would gladly see him dead at Hogwarts. But he takes the risk for reasons beyond the glory he could gain and knows he can take.
Meanwhile, Albus Dumbledore's attention is captured by this strange foreign blond Drumstrang upon the first glance and entranced even when only knowing his name.