So it's clear that I need to get stronger to clear Bravely Second. I can defeat Providence's first form, but his second form kicks my ass. So I bought the Growth Egg (costs 999999 pg) which doubles pg but stops EXP and JP growth. Then I go back to Starkfort, because the enemies are undead and can be killed with the Bishop's Benediction (heals all allies fully, which kills undead). Then I can simply get into successive battles (which require you to kill all enemies in one turn), until the chain ends and I get loads of pg.

After that, I intend to get the Golden Egg and equip it one of my other party members. Hopefully it means that I get loads of pg/EXP/JP so I'll get stronger. Then I'll go to Chompshire and buy equipment there (which costs 200000pg a piece) before returning to Via Celesto and getting vengeance upon Providence.