They belong together. Zoe is just too sane for Torg. Oasis fits his temperament. She's as flighty and air-headed and zany as he is. There's just no way around it. Another thing I've noticed: no matter how many people either Oasis or Torg have violently killed, neither of them seems to have their essential innocence of soul stained or aged or matured in any noticable way. They fit.