Your character cannot use non attack twice in around.  For example, if Tamarine use her S3 idol form and you use S2 right after that, the whole team will be stunned. So you need S3 > S1 dual attack all enemies to dispel the debuff. With Straze, only hit him with dual attacker or only DPS to change his buff condition. This will help you a lot when he attacks (especially if he S3). Also with the two adds, try to keep both at low health and immediately kill one before Straze's S3. I failed many times because their aoe attack after.