#another little headcanon I have is that his previous job was making tutorials

[trucksquared]

Minor theory I have:

I've never seen a regular deck of cards come with a rules card. But I have seen them come with board games. So maybe Rouxls Kaard isn't actually from the deck at all, and is actually from a board game

It could explain why he talks so weirdly (board game gimmicks), and doesn't seem to fit in with the other Cards. Who knows, maybe he'll even have some fancy Ludo powers or something

OH WAIT ANOTHER THING- both of his puzzles involved pushing a block to the adjacent square, like you do when playing a board game (though that could just be a coincedence)