Well I just beat the post game content (the stuff at the Sea Ark hotel, not the bonus disc dungeon yet). I mostly used the same team as I did for Manitou
>>12484047 except that I replaced Valkyrie by Hanuman. Despite having slightly better attack stats, both at lvl60, Hanuman hits less hard than Valkyrie for some reasons, BUT he has Rakukada (def+ buff) which turned out to be useful against a couple of bosses.
Meaning I was still using Haoma for healing and Peri for buff/debuffs, because despite all my efforts I couldn't find better replacements. But despite being lvl 53-55 they held their own real well and only died from OHKO attacks.
When necessary I also used Nemyssa for healing, with the high agility I gave her it meant she'd heal at the start of a turn while Haoma would heal at the end of a turn, thus ensuring constant healing before and after the bosses attacks, thus avoiding bad luck deaths when bosses used their best attacks two turns in a row.
The only exception to this was the boss which uses either magic or physical reflection at the start of each turn, but it turns out I had the perfect solution for that boss in my team already. For the longest time I thought the boss was reading my commands and using either magic or physical reflection depending on what would have dealt the most dmg on my part, but turns out I was just having SHIT luck and it's completely random. Once I figured that out, I brought Valkyrie in and after buffs/debuffs I had her and ONLY her attack. Because she too, has physical damage reflection, meaning that in the event that the boss reflects her attack, she wouldn't get hit (and die) from the reflection. Then it was just a matter of time.