Sheila: Eat swirly sticks of pain!
Thulssa Yii: No, thank you, I'm on a strict diet.

A bit of art I got from Brooke, the artist for the At Arm's Length webcomic. http://www.atarmslength.net/
In this event of dubious canonicity, Thulssa Yii encounters the heroines of the comic and Sheila, the fighter of the group, decides to try and rush the evil snake wizard. It does not go well for her. Thulssa Yii already seems to have some sort of grudge against kangaroos beyond his general disdain for mammals, but that's okay. There's always room for another turtle in his terrariums.
May not ever actually happen in the comic, but a man can dream, right?

In any case, Thulssa Yii does appear in the webcomic, so if you want to see (in this arc here: http://atarmslength.net/comics/931/) so check it out if you want to see more. And if you like the idea of a story about three magical ladies who have to balance domestic life with saving the world, check out the comic as a whole.