I would suggest exactly what
Orca said

If you dream something and you think it's bad.. that person you like is going to be killed whatever.. I wouldn't take any ACTION toward it.. if you want them to live.. just say.. "I prefer they live" that's all you have to do to make adjustments to the reality your living in.. you can't speak for other people

but you can vibrate to a new reality where they choose to stay
Why I pointed out the word
manipulation.. was because that's the exact idea the OP was talking about.. or in others words they may have also been talking about creating through dreams (don't bother.. just use LOA.. it's simpler!

)
My suggestion to you
dream and anyone else wanting to get into these plays of morality is to
not bother 
Watch a movie on it instead.. or that tv show
These are just a hold up from "the shift" and likely these ideas won't serve you in a positive way.. especially if you get caught up in morality games.. why bother to get into morality games of a psychic/precognition nature?? why not just become a Detective it's the same game?? just
different subject.
My suggestion to you is to live for fun, excitement and joy.. you won't find that much excitement in precognition and helping people.. (mostly) it's not that fun of a game
Does that clear it up dream?
Any questions?