My biggest advice is learn how to reparry. Just play the first fight over and over until you get the timing down. It will help you so much in all content.
Storm (Pyramid X) has a stun mechanic that inflicts a passive stun effect if a stun debuff is purified. But as @Riptide said above the reparry method works well too.
Comments
Archangel with the AAR
Ghost, because she won't trigger Masochism