In Shalour City, go to the Pokemon Center and talk to the man with green hair. He'll say, "I've been playing this totally sweet game recently. You play as some cool little dude, who runs around and whacks enemies to the beat of the music!" If you haven't caught it yet, he's talking about Harmoknight.
That was a neat little thing, there.
EDIT: Based on how far I've gotten, I've made an interesting discovery- it appears that through the storyline, it's said that Lucario was the very first Pokemon to mega evolve. This shows that Lucario is the face of mega evolutions, if you look at it from an in-game perspective. The Aura, babies.
![Heart suit :hearts: ♥](https://cdn.jsdelivr.net/gh/twitter/twemoji@14.0.2/assets/72x72/2665.png)