In the 5 or so parties it took until I cleared, here's what I found worked best. In all of the groups I was in, we have major issues with DPS dying/not being strong enough.
Mark the Northwest corner with A. Northeast with B. Mark the center of the map with C.
Have the MT tank Nidhogg between A, B and C if possible.
Phase 1 - Angry Dragon and Big AOEs
Keep the party around C if possible. When mechanics happen, dodge the eyes/circles and prepare for either the "run to the middle line" or to run out of the big aoe. Like Warren said in his, it's easiest to run out from the middle, which cuts out about half the aoe.
Phase 2 - Adds
This is where most of the groups I was in struggled. We had consistently weak DPS and couldn't kill the adds fast enough. What I found worked best (assuming you have either a caster or a ranged DPS so that get an AOE Limit Break) was to have the party down the Shadow Dragon first. That's the one with random aggro. Then, MT would take another add and run to A. OT would take the last add and run to B. Keep them in A and B and faced away from the party until the Shadow Dragon is dead. Pray to your gods you have at least one LB bar. Once the Shadow Dragon is dead, move the tanks together. I typically told B to run to A to keep it simple. (Or we'd meet halfway). Regardless, once the last two adds were stacked, LB them. Don't wait for a second bar if it's not super close. Have everyone focus on one mob (mark 'em if needed) and then the other after Limit Break. If the healers are good, ask them to DoT or Cleric Stance if they can squeeze it in. Have the OT switch to an offensive stance to help kill off the MT's add.
With any luck, you'll get them down before Nidhogg decides to wipe the party. STACK UP.
Phase 3 - It's basically Ravana?
This was the easist phase in all the groups I was in. For the most part, it plays like Ravana story mode. Have the MT not die while people hit him as hard as possible. When the circle markers appear, run them into the corners or edges, giving people plenty of room to dodge the lines. Be ready for a second set of circles if unlucky. The phase will basically repeat. When Nidhogg starts getting really mad, he'll jump and you'll enter the last phase.
Phase 4 - DON'T FUCKING LEAVE THE STACK
The title basically says it all.
This phase is basically the first one with 3 new moves.
1) Annoying fireballs. Don't touch them
2) tail-whip Heat tail or whatever. It's the opposite of the heat wing. Don't be in the middle line after the eye/circle things.
3) Akh Morn (suffering). If the whole party doesn't stack on this, YOU. WILL. WIPE. For some reason, people freak out when they see the big "EVERYONE STACK ON THIS PERSON" marker and try to run away. Kindly advise the party to just run to C when this happens. It's marked and they should be able to find it easily enough. DON'T. MOVE. You can still attack Nidhog while your healers use every AOE Heal/Spell they ave to keep the party alive. Cure 3 is your friend if you're a WHM. Don't bother with Medica or Medica 2 due to cast time. Have your BRDs or MCHs do their mana thing.
Nidhogg will then continue everything he's done this phase over and over. As long as people remember to stack up and dodge when needed, it's really not that bad.
Phase 5 - There is no Phase 5
You did it! Enjoy the cutscene or watching people flip their shit because they killed the big dragon.
Mark the Northwest corner with A. Northeast with B. Mark the center of the map with C.
Have the MT tank Nidhogg between A, B and C if possible.
Phase 1 - Angry Dragon and Big AOEs
Keep the party around C if possible. When mechanics happen, dodge the eyes/circles and prepare for either the "run to the middle line" or to run out of the big aoe. Like Warren said in his, it's easiest to run out from the middle, which cuts out about half the aoe.
Phase 2 - Adds
This is where most of the groups I was in struggled. We had consistently weak DPS and couldn't kill the adds fast enough. What I found worked best (assuming you have either a caster or a ranged DPS so that get an AOE Limit Break) was to have the party down the Shadow Dragon first. That's the one with random aggro. Then, MT would take another add and run to A. OT would take the last add and run to B. Keep them in A and B and faced away from the party until the Shadow Dragon is dead. Pray to your gods you have at least one LB bar. Once the Shadow Dragon is dead, move the tanks together. I typically told B to run to A to keep it simple. (Or we'd meet halfway). Regardless, once the last two adds were stacked, LB them. Don't wait for a second bar if it's not super close. Have everyone focus on one mob (mark 'em if needed) and then the other after Limit Break. If the healers are good, ask them to DoT or Cleric Stance if they can squeeze it in. Have the OT switch to an offensive stance to help kill off the MT's add.
With any luck, you'll get them down before Nidhogg decides to wipe the party. STACK UP.
Phase 3 - It's basically Ravana?
This was the easist phase in all the groups I was in. For the most part, it plays like Ravana story mode. Have the MT not die while people hit him as hard as possible. When the circle markers appear, run them into the corners or edges, giving people plenty of room to dodge the lines. Be ready for a second set of circles if unlucky. The phase will basically repeat. When Nidhogg starts getting really mad, he'll jump and you'll enter the last phase.
Phase 4 - DON'T FUCKING LEAVE THE STACK
The title basically says it all.
This phase is basically the first one with 3 new moves.
1) Annoying fireballs. Don't touch them
2) tail-whip Heat tail or whatever. It's the opposite of the heat wing. Don't be in the middle line after the eye/circle things.
3) Akh Morn (suffering). If the whole party doesn't stack on this, YOU. WILL. WIPE. For some reason, people freak out when they see the big "EVERYONE STACK ON THIS PERSON" marker and try to run away. Kindly advise the party to just run to C when this happens. It's marked and they should be able to find it easily enough. DON'T. MOVE. You can still attack Nidhog while your healers use every AOE Heal/Spell they ave to keep the party alive. Cure 3 is your friend if you're a WHM. Don't bother with Medica or Medica 2 due to cast time. Have your BRDs or MCHs do their mana thing.
Nidhogg will then continue everything he's done this phase over and over. As long as people remember to stack up and dodge when needed, it's really not that bad.
Phase 5 - There is no Phase 5
You did it! Enjoy the cutscene or watching people flip their shit because they killed the big dragon.
