in the sense that you alter a fate-line (for want of a better word) have an energetic toll on the magician working the act. All magic is about flow of energy in a fundamental sense and not only does the act require the magician's energy, but so does the sustaining of the altered fate. Make the blow specific and over with quickly.
Secondly do not engage in the same long drawn out "I can change them forever"bullshit. The cost to you of maintaining that breakaway fate line will swallow you eventually. It sounds trite but the old saying; " you can only change yourself, not others" is really great advice here. Even though magicians of skill can manipulate the fatelines of others the energy to do that long term is ridiculous and pointless.
No magician's true will and purpose is served by coming up with new and costly ways for them to be able to endure assholes in their lives; to manipulate who they are in order to accept the unacceptable.
Lastly everything happened already each of our is just an actor in the game of life pulled like a puppet by the puppet master(DNA).Our past lives control the current and our future lives also affect the past but really each "push" is 100% was supposed to happen.In a way the whole purpose of initiation and death ceremony is keep you "awake" to see all your past,current,future lives as pictures tagged on a huge wall, image-to-image and you can see everything like an adventure and each person in your past,current,future life just become an initiation officer.Basically you can't change anything(only relax and let go of life), you can only experience(and widen that experience by occult/magic means).