Pyromania
Wayvern was bored out of his mind. He was amazed that Celestia had the patience to govern a kingdom as quiet as this one daily. That changed when Twilight came rushing into the throne room panting like she just ran a marathon.
"Wayvern! We've got a Kaiju attacking Ponyville!" Wayvern was regretting his desire for excitement when he heard "Kaiju." He immediately rushed to Ponyville as fast as his wings would take him, and found the Kaiju burning everything just by walking by it. Wayvern started the fight with an Alicorn Magic blast to the face, which knocked him back a few feet.
"One of you actually has the nerve to fight back, eh?" He said. "This place just got a lot more interesting."
"I am Wayvern, King of Equestria! I will not stand by as you murder my innocent subjects!"
"Is your army so weak that you have to fight your battles yourself!?" he raised his arms. "I am Pyrhon! Kaiju of the Flame Dimension! You will die for standing in my way!"
"There's a lot you don't know about me!" Wayvern raised his head, and recited the incantation. "I summon the Blade of the Seven Lights and the Form to use its Power!"
The fight started with Wayvern clashing Humming against the gauntlet of Pyrhon's Armor.
"A hunter!" Pyrhon shouted. "Why would a hunter be here!?"
"Ask your king if you get the chance to see him again!" Wayvern yelled. He broke the struggle and they jumped to the top of the Clock Tower and the Town Hall. Wayvern leapt off the town hall roof, and swung Hummingbird to keep momentum in the air. Dodging Fireballs shot from Pyrhon's wrists, sometimes batting them back or away, was hard with no ground to control the direction you move in. Finally Wayvern found the weak point of Every Kaiju, the Core, and Split it down the middle with Hummingbird. But that alone is never the end of a Kaiju. Pyrhon just got bigger. Wayvern was in trouble, he didn't remember how he got rid of the Giant Kaiju. Until he remembered Babylon and the Colossal Sword.