[Den-O]

Why does any of that even matter? In this universe those things exist, why question how they exist or why they function? They simply do. Do people question why there's a time travelling train in Den-O? Sure, but the answer simply is there just is a time travelling train. No one questions why fangire exist in Kiva and have a hierarchy based on kings and queens. They just do, that's the nature of their race. Or how on Earth Kanzaki Shiro created high tech card decks and suits of armor for people to fight a rider war in Ryuki, when he was just a college student. He just did it, it was a basic premise of the series. Things like that don't always need ot be explained. You're looking way in depth for something that doesn't really need an explanation to be valid. That's just the way things are in Wizards' world.