Gajasimha seems to lvl up when it cure or buff itself. Fulmination <35% (even without lvl up) and can spam it. Can be Silenced/Stunned.
Old Shuck was very easy with a melee/smn zerg setup, melees/avatar could still hit reliably after several lvl up. Sadly we haven't found a way to prevent the howls and our strat involves to use some SPs.
Bashmu uses only physical shield when the first head is cut.
Sarsaok is very weak to magic and very resistant to physical dmg in general. Maybe there is a way to change that a bit like with the Delve Panopt NM.
Ecliptic Growl protects from Mimic/Harpy potent all stats down TP moves, maybe Braver's Drink too?
Yakshi doesn't have a high Regain before using Cordon of Apathy and can be rendered harmless with Mewing Lullaby strat, has 800k~ HP with 9, starts using Elemental Sforzo at 49%.
I tried some Spinning Dive BPs with Rolanberry Daifuku, Drachen and Bolster or BoG Torpor and couldn't hit at all (aura was present too) while I have no problem to hit anything else in the game now aside of Vir'ava, Kirin and probably WoC, I don't even need acc food/buffs/debuffs for stuff like SR or Vagary. I fear that the accuracy requirements may be very/way too high but really hope to be wrong. Fully buffed DNCs, BLUs and RNGs can reach higher acc levels than my avatars too.
This NM can be popped by fishing in the black orb that pop during the night. Can be fished with Ebisu+1 and 110~ skill but someone with 104 skill couldn't, someone else with Ebisu and 96 skill couldn't either. Drops Exemplar.