Come to think of it, in Expert there should be only 3 mobs, so that might not be enough to build to Full Burst. You might have to modify accordingly.
Some thoughts:
Use all your light kamihime and pair them with Amon (affliction protection) and Indra (affliction removal). Use Van Helsing with Maiden's Prayer for an additional affliction protection. Use Amon's affliction protection immediately and kill the 1-charge overdrive enemy, then the 3-charge enemy, letting neither of them use their overdrive. Try to time it so it takes 4 turns. Taking the remaining enemy down should take 2 more turns, but hopefully longer. When the boss fight begins, spam skills to reduce her HP and force her into Rage ASAP. You have 2 turns to force her into Rage (and 2 opportunities to prevent Petrification), at which point you should be ready for a full burst. Your Burst should force her into Stun immediately. Amon's Protection CD should be up again, now giving you a 3rd block. The entire fight should be over in 4 turns, and if it's not, she should be sufficiently injured that you can finish her off with intermittent auto-attacks and skills. Indra and Van Helsing's cleanse should give you a 4th opportunity to remove Petrification at some point.