Difficulty spike?

[Melondra]

he's got a enrage timer in his final phase if I recall

[Neophyte]

If you struggle to beat the adds dps check, just use the LB1 (either melee on one or mage/range on 2-3). Kill the random attacking first, 'cause this one can lower your dps on other adds by forcing you to move.

If you hear a thunder-like sound the circle 'Eye'-AoEs will appear -> run.

Stack the whole time while Akh Morn. Stack behind him, have the tank move to you. Place a area mark if you have to.

First/Last phase everything from almost the center of Niddhogs enemy circle up to the edge where the tank stands is a no-go area.
Like Sephiroths half arena cleave his firebreath can hit you there.