It's pretty simple, really.
Red Wizard twinked.
And fiddled.
And optimized.
And powergamed.
And ground in added dungeons found in various alternate versions of his game.
And Yukimaru simply exploded upon entering the arena.
Sure, it wasn't legal.
But when you spam your catchphrase that much? The judges get really sick of it.
And by judges, I mean Rozalin. Connections are useful.