Well, on the bright side you have 2 weeks to do it. Considering how stamina-heavy event maps are (and dailies outside of Wednesday and orbs), you'll have plenty of charisma to use on story maps for leveling fodder.
Me, I was careless and noticed too late that the little ones had a ranged attack and let Garania die <.< 2*, will get 3* next try, most likely. Haven't tried the VH one but I'm not expecting much issue since it sounds like my Nanaly, Minerva and Aisha will wreck them before they move