No, having all of your party members wear Black Belts is much more important than having tons of life. That bloated esper likes to cast Disablega fast and often. If your party gets hit with that, then there is no healing, and with Sap and him smacking you, you are gone.

Setting your support characters to healing (with one possibly attacking every now and then when everyone's HP is good) and at the ready with Raise and Phoenix Downs is a good idea, while your tank uses regular attacks on the Impure King. It may take a bit and cost a bit in MP, Phoenix Downs, and time, but it is a well-grounded method.

That is not an answer at all to your original question, eppy19, but it may help.