Living in Equestria under a false name and racial identity is one thing. Finding out you're not the only one of your kind stranded here is another... especially when that someone and the element bearers are looking for you.
Twilight has developed a device that can detect strange signals coming from outer space; signals from aliens! She gathers her friends so that they can all listen in. But they may not like what they hear...
A human soul is stuffed into King Sombra's body. Having no idea what's going on, and thinking he is in some kind of coma, he just casually strolls into the Crystal Empire.