Love ball with star seal
The Malfunctioning Sylveon.
Glitch is a friendly, playful, and super fluffy shiny Sylveon. His fur is lighter than most Sylveons - even out of the shinies.
Most Sylveon are quite secure in their affection by nature, but Glitch in particular... has some issues with emotional permanence.
It was believed that contracting Pokérus while he was young may have altered the stability of his Affection stat.
When Glitch feels insecure in his Affection, the value is glitched, leading to a MissingNo.-esque devolution to a shiny Eevee. His entire form pixelises and hue-shifts, sometimes showing MissingNo. before reverting to his childhood shiny Eevee form - light grey, with blue eyes.
His Eevee form can sometimes appear unstable and staticky.
Reminders of affection, like love notes or collars, can help keep his form stable! ❤