I just managed to beat ragnarok without reviving.

36k atk power. ~20% wind atk up from weapon skills.
Jean with black propaganda, Gaia, Zephyrus, Cybele, Brynhildr and in the back Heimdallr and Hermes. (I lost brynhidlr, when I got her to 1/3 hp)

The ability to cut down burst by 40% and lots of attacks debuffs are working really well.

Her rage burst is just dealing little over 1k with all 4 atk debuffs + 40% dmg cut and plus Rahabs thunder resist. (without Rahab it's little over 1,5k)
Non rage burst is ~2k on Gaia (with dmg cut and motherland+) it's great that her Eternal Gale heals it back.