Hogwarts Underworld

Helios Corvinus, Cassandra Worley, Neville Longbottom and Luna Lovegood, who were students at Hogwarts, established the Hogwarts Four Houses Alliance and became what Hogwarts students later called the Hogwarts Big Four in the new era. After Dumbledore's death and Voldemort's ravage of Hogwarts, many wizards sent their children to other magic schools, and Hogwarts could not recruit new students. At this time, the four Helios stood up and announced to the world: "Want to learn our magic? If you want, I can give it all to you, go find it! We put all the magic in Hogwarts."