See... There is absolutely no role or strategy for Gardevoir (or Mega Gardevoir) to fill in any capacity, any situation, and on any team that can't be better performed by a slew of more qualified Pokemon (or Mega Pokemon). Seriously there isn't. It's not an opinion, it's a mathematical and strategic fact! Not as an offensive type, not as a gimmick, not for defense, not for support, nothing. EVERYTHING she could do could be done by a better Pokemon more effectively and safely. Eternally NU tier. But she's still a waifu.
And Shiny Mega Gardevoir is just fucking overkill on awesome looking cool ass monster girl time. And it makes me mad because shiny Pokemon are like digital fedoras.
I love/hate Gardevoir because she's everything I want in a character design and nothing you'd want in serious gameplay practice. UGH! FUCK. ARGHHHHHHHHHHH but remember, you should ultimately use the Pokemon that you WANT to use!! You don't have to be a Smogon shit like me. You can play for cutes. That's awesome if that's what you want to do!
Fucking... this Pokemon tho... Fuck! So cool.
24 Hour Later Edit: I laugh at everyone here who thinks they have a legitimately tournament capable Gardevoir. Pokemon isn't fucking YuGiOh you can't believe in the heart of your Gardevoir and it can suddenly rise from the very bottom of NU tier and take out Exodia. No. And Mega Gardevoir no. No one's wasting their one Mega slot on her.