Well when you think about it it's moved more towards fantasy. Viola is a fortune teller, ZWEI's a werewolf, Raph is a Vampire, Voldo... Is Voldo (Or a human spider), Ivy's an alchemist with a living sword, Nightmare's a parasitic sword, and there's still more. I'm sure adding a more magically inclined character to a series that already has so much magic and fantasy wouldn't be harmful. And even with all of the magic and fantasy, there's characters who are more realistic, like Mitsurugi, Siegfried, Setsuka, and many other characters, as much as they come and go. I don't think balancing the fantasy and the realism isn't an issue.