Oh, I was under the impression it only changed your destiny if you didn’t know who you were like trying to find the person you should be lol
Change destiny could also make a person who has a great destiny turn out to have a bad destiny.. It can be changed depending on the caster I would think..
Problem being it's not you average genjutsu where some1 can just ki chakra shock you out of it but you would be somewhat programmed to do what the caster desires you to.
(Example bein Itachi knew Kabuto was a shithead so he cast genjutsu (Izanami) to program the opposite of a shithead. It should or could work vise versa)
The ultimate MKultra program..
It's what i picked up from it but i could be wrong..