Final Submission
Crucibelle, the Ceramic Pokémon
X/OR: It lives in ancient ruins. Many a Trainer has been startled when a seemingly lifeless clay pot opened to reveal a hidden Crucibelle.
Y/AS: Its body is bright purple due to the toxic mineral salts it contains. The more vivid a Crucibelle's colour, the more potent its poison.
In previous CAPs I've seen people frame their X entry around life (because Xerneas) and their Y entry around death (because Yveltal). I've tried to do something similar here - the X/OR entry is about where Crucibelle lives (> life), the Y/AS about its poison (> death). This also leaves me with the X/OR entry discussing its Rock typing and the Y/AS entry discussing its Poison typing, which seems nice and symmetrical.
(Also, yay! I'm glad my feedback was received in the spirit in which it was intended.)