Rivals

[Lemmy Koopa]

Ludwig von Koopa vs Bowser Jr. (Brotherly Rival) : I can see this happening. Bowser Jr. pretty much replaced Ludwig for the title of the Koopa Heir and since then has became a nuisance. Even though he's forced to get along with the brat, he still doesn't like him.

Ludwig von Koopa vs Luigi (Conditional Rival) : Luigi isn't as respected as Mario is and Ludwig practically enjoys the fear that the younger brother has. The only time he'll ever be on Luigi's side is if they are to fight off a bigger threat together, but other than that, yeah.