You have a pokemon friend from your birthday. After care about her so much makes your pokemon evolve to Gardevoir and now she are the one who protects you with her whole life... but actually it's annoying by her overprotective behaviour, so mostly you trying be alone than with your pokemon...
Yes, your pokemon can talk through her telepathy, so you are always can understand what she want or need even when she are pokemon, but not human
You can also mega evolve your pokemon, since you have mega ring with Gardevorite!
Your Gardevoir actually using yourself on maximum (So dealing damage to enemies always so high and etc.), but she can't properly control her energy. So after few using her power she can quickly waste her energy...