This series is just crazy and I love it. Blowing into a whistle to buff yourself, and getting inspiration from clearing a video game when the world is ending? LETS GO
He goes and plays Dragon Quest to prep for end of the world, and... it works! Sure, Pan is badass, and won that fight with gusto, but I think Arthur's state of mind had an actual effect on that combat. Arthur might actually be the most OP character in a world where subconscious thoughts shape reality. I mean, his own power itself is gated only by his subconscious.