Used in some religions.
Some teens and adults on tiktok adapted the term to mean moving your subconscious to another reality. In truth, it is just lucid dreaming. The fact that you have to go to sleep first says it all. They took a term used for religion and coined it as a way to bang fictional characters. It's quite annoying. They'll argue that it's not lucid dreaming and that they're actually there but in reality it's the same thing with different names. Or they're just daydreaming. Most of these "shifters" you'll find on tiktok or youtube are young. No younger than 12 and no older than 25. It can be damaging to ones mental health. If you really want to meet you favorite fictional character then write a story or just daydream or try to lucid dream.
Person A: Whats shifting?
Person B: Lucid dreaming.
Person A: Why is it called shifting then?
Person B: Because some people wanted to believe that they can travel to other universes.