quick question i got on my mind

What if you say over and over to yourself as you go to sleep and after"after i fall asleep i battle the boogeymen in the movies that could of went to boogeyman to hell in the movie world!"Would it work?I am not sure.Most likely you might just dream it.

That’s how mantra works.

This is called dream incubation. I’m not sure what you mean with “you might just dream it”. It is certainly possible to convince yourself into dreaming something, and it is also possible to become lucid from it when you recognise the scene.

The best way for me to make myself dream something is, strangely enough, to imagine that I write the dream down in my dream journal. Telling yourself that you will dream this also works for many people.