Boss 10 - Entrails Parasite
Boss 11 - Dispater
Boss 12 - Bladehorn Boar
Boss 13 - Veres
Boss 14 - Kurt
Try to keep his attention focused on Asbel so that your mages can do their best to hurt him. He is tough to stun but when you do, make sure you take the opportunity to hit him with every attack you have available. An All-Divide item can be used here with varying results. You will cut down his power but also your own. The problem is that his attacks will likely still be so powerful that you won't gain much by using it. Your best method here is to just defend like crazy and attack during the brief windows he gives you. Be prepared for a long fight and make sure you have a bunch of Gels and Life Bottles.
Boss 15 - Richard (second encounter)
Boss 16 - Polycarpus
Boss 17 - Lambda
Boss 18 - Centuroid and Veritoid
Boss 19 - Richard (third encounter)
His Eleth Burst should also be avoided as much as possible. His special attack during Eleth Burst will drop one person easily and will likely take someone else out as well. Your offense is the best defense here. If you can keep him stunned for most of the fight it will go by easily. If he spends too much time running around, things can get crazy. Do your best to keep him stunned and not let that happen.