>>25072701The make up and ear thing isn't half bad, shame about the rest of it.
>>25072741The most plausible theories usually center around a gardevoir taking its protectiveness to the extreme. If their beloved trainer is almost suicidally reckless and causes them a lot of stress as a ralts they might try to overcompensate. If this ralts also learns that it can maim and kill to get something to stop bothering it and its trainer, even accidentally, it might spell disaster.
The moment the other pokemon do something that loses the Gardevoir's trust or even unintentionally endanger the trainer to a great extent, this gardevoir might figure that it's better to make the others disappear for their trainer's safety.
That aside.
I think a yandere gardevoir would operate a lot like Gasai Yuno, who actually isn't like most yanderes in that she'll mostly only do the crazy murder shtick if you do some top level betrayal, or also do the murder schtick yourself. Which boils down to life or death situations. They won't kill a love rival or something, although they wouldn't be above sending them away through other means.
That or they would just isolate you from everyone through subtle psychic manipulation and house arrest style stuff.