*nervous sweating despite the fact I'm gonna be using a Popplio*

Nuzlocke? never heard of that or those.

The basic rules of a nuzlocke:
If a Pokemon faints, it dies and you either box or release them
you can ONLY catch the FIRST Pokemon you run into PER route
and you have to nickname your Pokemon to get more attached to them

Meaning you can lose a game under those rules.