I'm going a bit obscure on this one...but I usually do. I love the Paper Mario games (mostly because of the RPG feel) and I instantly liked the Shadow Sirens/Trio from Thousand-Year Door. They're purple ghost witches...which are 3 of the coolest things you could possibly be in the history of cool things. Vivian is my fav but that's because he/she is so adorable!
Anyway, enjoy some "sisterly" interaction.