Tank the two remaining adds to the sides, positioning their AoE cones outside of the arena.Move away from the add before it swipes to avoid this extra damage. Middle add can't be tanked and will attack players randomly with an unmarked, short range frontal AoE telegraphed by him preparing to swipe at a player.(A wipe is when the players die and the battle has to start again from the beginning). If adds are killed too slowly, or not killed at all before Nidhogg blasts players back, it's a wipe.
Since the room is massive, it's recommended to stack in the center of the room every time Nidhogg flies away, then spread out to avoid the AoEs, thus ensuring you can get positioned in time. The holes will spawn first, Nidhogg will disappear and you will be able to see from where he flies to where the trail will go.
Run out of the holes that spawn under the players, as these will do massive damage to any player caught inside of one.It's recommended for casters to stay within AoE heal distance of their healers at all times, preferring to avoid AoE damage where necessary. It does approx 4k dmg each time to the entire party, and in later portions of phase 1, will be cast twice in a row. Nidhogg will do a Deafening Bellow every so often throughout the fight.This will be a huge AoE blast of fire, followed by a room-wide AOE with a safe line along the length of Nidhogg's body. Avoid the flyover AoE and "Hot Wings" AoE.This encounter can be especially tricky for those whom have only done Main Scenario Quests, as coordination and positioning are critical, especially during the second and final phases. Those without experience in Alexander or Containment Bay S1T7 will need to pay especially close attention to positioning cues that may be unfamiliar during the final phase. Positioning of all players is crucial to your success in this fight, as several lethal AoE zones will be cast in quick succession that you may not be able to avoid with poor positioning. Unlike the previous encounter in The Aery, this fight has four phases that combine healer checks, DPS checks (DPS checks are where your party has to do enough damage within a specific amount of time or you will die), and raid mechanics (such as stacking to share damage).