“The great hulk of the scaled beast lay wheezing before me, and I am not ashamed to say that I was frightened: though it was injured, I knew the dragon could easily tear me in twain. The young monk, however, knelt beside the creature’s head, whispering to it in a strange growling tongue. I questioned the woman, but she ignored me completely, engrossed in examining the scaly monster. After much badgering, she said merely, ‘I do not mean to be rude, but you are quite a distraction. Please, leave me to my work.’” -Jeron’s Great Journeys, Book III, Chapter 4
Believable magic, like ordinary physicis, operates according to some invariable laws that always result in some kind of cost or "bounce back". The grater the magic, the more it should cost the character physically, emotionally, and spiritually.