Wow, the group picture, Pauline and Rosalina look great! I don't know if it'd be a bother but the Wario spin-offs have got some other really cool girls like Ashley and Captain Syrup! I think they'd look amazing in your style as well if you're looking for something new!
I know this was asked a while back, my apologies 🙏 I get extremely busy.
"Cappy has made no appearances since Super Mario Odyssey"
Actually, this is a bit of misinformation. Cappy is a Bonnetor, known for being able to disguise as any hat/headwear, and possess (or "capture") the person wearing them.
The Mario franchise has an enormous cast of characters, many of who wear hats (it's a bit of a theme for the series). Just look at the size of the cast in the recent game WarioWare: Move It!
With so many characters, just about anyone with a hat could secretly be possessed by Cappy.
Sure, maybe they'd have to have red eyes, since we saw enemies get blue eyes when Mario captured them, but still.