Why does my Zorua in BW2 sparkle when it enters battle at the back of my party?

Question

In BW2, I recieved N's Zorua. Whenever I use it when it isn't in its Illusion form (by having it at the back of my team) and I send it out, it sparkles, like a shiny Pokemon. I know that it isn't a shiny, though because it has a different shiny animation to other shinies, it looks like a normal Zorua and it isn't marked with a red star like other shinies when you view its summary. Is this meant to happen, or is it a glitch?

Answer 1

Upon encountering one of N's Pokémon, the game will notify by showing a sprite entry animation that is similar to the Shiny Pokémon sprite, but instead has its own sound and green and yellow diamond lights.

source
Apparently, this animation plays whenever one of N's Pokemon enters battle.