On my free summon I got a +atk,-res, but I already have a +atk,-def. Which elincia is better?
I would suggest keeping her defense so she doesn't take too much damage from units like Hector (both of them). I have a +ATK, -RES Elincia myself and she tears through green units like tissue paper. I don't run ploys on mine and I want to keep her physical bulk. Personally, +ATK, -RES is my preferred choice.