Carol is right handed (she puts her right hand on Kris's shoulder), the Knight is left-handed (sword in left hand) and Dess is left-handed (the mouse in her room is for the left hand).
A katana probably would turn into something else in the dark world. And it doesn't look like a Katana at first, it looks like a baseball bat. Dess has been said to use a baseball/wiffle bat
Dess also has antlers
