Harry Potter and The Immortals

Dumbledore is short a DADA Professor, and that means the Ministry gets to intervene with Hogwarts, so McGonagall decides to call on an old friend from long ago to help out. With Maiza unable to fill the position, enter Firo Prochainezo: an Immortal wizard, member of the Martillo Family, and unwilling to put up with a certain pink toad who holds the title of "High Inquisitor".