An eighteen year old boy wakes up one day, only to discover that he's not in his own world anymore nor his own body.

Biased off of Steins;Gate. Okabe and kurisu were attempting to set up a remote time travel device but when the machine went back in time, the world line shifted dramatically.

Not long after returning to Equestria Luna meets the doctor.

1000 years ago Luna submitted to her jealousy of her older sister, becoming Nightmare Moon. When Celestia used the elements to seal her away in the moon it didn't just seal her.

Have you ever gone to sleep late at night then woke up 2000 feet above ground in another dimention full of colourful equines? Well I have and it's not fun, now I have to try to find a way back home.

A teenage girl wakes up one morning only to discover that someone else is in her head. Now she must go through normal life while at the same time try to reverse it.