Who let this evil dragon into Hogwarts!

When war reignited in the wizarding world, and despair ignited the dome of Hogwarts, all centaurs, werewolves, and all persecuted magical creatures ceased their silence and cried out in unison the name—the invincible Scourgewing! The Emerald Lord who rules over all spirits! We beseech your arrival… we beseech you to bring equal death and despair upon wizards, upon the wizarding world, upon the entire world! …“In conclusion, Your Excellency Minister Persson. Some have accused you of being the true mastermind, the instigator of the riots, the treacherous, manipulative green dragon.” “These are all baseless accusations!” In front of the various newspapers, Persson spread his enormous dragon wings, his emerald scales shimmering in the sunlight. "This is all Voldemort's frame-up! He wants to use this to defeat me, defeat you, defeat this magical empire that's about to conquer the world!" "But he's wrong!" "Only I can bring true equality, only I can allow every wizard, every werewolf, even every goblin, to live freely in the sunlight!" "Let magic be great again!"... Watching the colossal wings that blotted out the sky disappear into the distance, Dumbledore, sitting in the Headmaster's office, sighed softly, a rare hint of alcohol on his breath. He looked at Voldemort, already imprisoned on the display stand, his screams never ceasing, and muttered to himself, "Perhaps I shouldn't have brought that demon king into Hogwarts back then..."