+def/-hp or +atk/-spd Ayra

I would go with the +Def Ayra. she would easily get into desperation range with less max hp. she only has 1 less physical bulk against being one shot and she is already pretty bulky on the physical side anyway. her weapon ability and special activates on speed so you most likely don't want to hurt that stat if you can help it.

+def is great on Ayras. In my option, it is better than +atk as most of her damage comes from the special.