Liz is a smart girl. She knows what she's doing, with only just enough drive for heroics and exploration to get her into (and out of) trouble. However, no matter how skilled you are you aren't ready for a swarm of unown to rip apart the fabric of reality and throw you into an unusual new world! Thankfully, the natives are understanding and quite helpful.
The issue comes up when her Pokemon team are spread far and wide across Equestria, and don't adapt to their new surroundings quite a readily as their trainer does.

(Pokemon/MLP crossover. Rating of 'Everyone' is pending at this time. If this story proceeds in a way that makes a 'Teen' rating more accurate, I will update it.)