Melody's unusually accepting of Warlock influence on the life of a young girl (even one who becomes a Shadowhunter), courtesy of her mother's friendship with a sorceress.  Melody never formally lived with or was cared for by a Warlock, but she absolutely associates that family friend with fun vacations and relaxed good times.  Depending on how much stigma you were wanting Ksenia's past to have attached to it in Shadowhunter circles, Melody's belief in Warlocks being<em>people with whom one can spend time</em>might have been rather welcome.<br/><br/>She's also a nerd who enjoys sparring... though that is probably not so distinctive a feature.  ;)