Chapter 9: Discordance
Make Leda a Dancer before battle and keep enough healing. Stabilize when the beast turns hostile, clear the lower-left threats, then finish Cai.
Change Leda to Dancer before battle, and keep a healing slot for Sofia even with a reduced deployment. Buccar turning hostile costs you a front-line unit. When the beast also turns hostile, let Leda hold it off while you restore the party. If your Resistance is high enough, clear melee enemies first and pull back slightly while the third faction fights the enemy. Clear the lower-left enemies and protect your back line before approaching Cai, then let Mu land the finishing blow.
Return to the Leda route walkthrough
Use the necklace to make Leda a Dancer directly
Once you obtain 
Dancer's Necklace, 
Leda can qualify as a 
Dancer without an exam. Dance lets an ally act again. Still, if Leda can defeat the enemy in front of her herself, she can attack directly instead of always passing her action to someone else.
If you use this chapter's free time to bring main units to level 35, prepare Advanced Licenses early. Return to town to change class as soon as they reach the target instead of continuing to earn EXP in caves. 
Catania can become a 
Ranger, trading some Strength growth for the Attack Speed advantage needed by the passive. Change 
Sirocco to 
Ovate before the main battle.
Adjust deployment around your healing needs
Buccar is forced to deploy and turns hostile after battle begins. You will need another armored front-line unit afterward.
Approach 1: If your main units are well leveled, remove lower-level members and reserve a healing slot for 
Sofia. A reduced party left with only five units after Buccar turns hostile lacks recovery in the middle and late stages. Do not cut healing too.
Approach 2: If your original roster has several healers, remove one and add a combat unit to replace the strength lost when Buccar turns hostile.
Let Leda engage when the beast turns hostile
When the beast turns hostile, have Leda hold the front while you heal your defenders. Stabilize before advancing again. Use the Cleansing Blade against enemies with Underworld Boon. Before battle, give it to someone who will be able to use it.
The third faction fights other enemies. Pull back slightly during the melee and let the engaged forces wear each other down. If your party has enough Resistance, prioritize melee enemies and leave mages for later, spending actions on more dangerous close-range threats.
Clear the lower-left enemies before attacking Cai
As you advance toward 
Cai, check the enemies to the lower left and remove those who can reach your back line before bringing healers and other rear units up. If you focus only on the front, those enemies can reach your back line. You can leave the last hit to 
Mu.
Cai
Buccar
Ultand
Peter
Tialla