I'ma copy and paste what I wrote in another thread:
--FIRST FORM (Eald'narch, Exoplates, 2x Orbitals)--
About the Exoplates:
Exoplates have no standard attacks, and can only use WS's, which are physical and can be blocked by Utsusemi. Every 33% (including the final 1%), they will use
Phase Shift, which is a strong, large range physical move that has a long stun effect. RUN tanks should aim to have Tellus Pflug going at those 33% marks in hopes of reducing the Stun proc/duration.
Because Exoplates are not independent, the hate they accumulate is arbitrary; any damage dealers need not worry about holding back on them. Exoplates also are very magic resistant from what I've seen with Lunge.
About the Kid:
With the Exoplates down, he's no longer invincible, and actually really pathetic. The kid does not have any TP moves or standard attaacks, only casting (with no fast cast), which is either ancient magic or Sleepga. Assuming your damage dealers are /NIN, they are quite safe to pull hate provided they are not slept or for whatever reason have Orbitals attacking them. Tanks should conserve time-sensitive defensive JA's for the next phase of the fight.
When Exoplates are up, the tank need only maintain enough hate to keep the kid off the healer, as this is the only other person who will have any hate on him. In the meantime, the tank can be meleeing the Exoplates. The kid's defense, evasion, and HP are all quite poor, and he can be paralyzed, possibly other statuses may work but I haven't payed attention.
About the Orbitals:
These are the only things tricky about the first form. The first pops as soon as the kid is aggro'd, the second about 5-10 seconds later. They have an extraordinarily large aggro range and seem to prefer going after people in the back, hence why only the tank runs in at the beginning until both are spawned. If killed, the kid will resummon them fairly quickly.
They can be slept, I have found Lullaby and Light Shot both reliable (haven't tried other sleep forms), but will build resistance over time. Their attack speed is rather high, and they seem to possess triple attack. Depending on the skill of your tank and what kind of support you have with you, it can be possible to super tank both Orbitals, especially during defensive JA's like Battuta.
If super tanking, make sure to switch to the kid before the Exoplates die so you don't develop hate on the Orbitals, exposing your healer to a beating. Their movement speed is normal, so in an emergency, it is easy for someone to kite both around the large crystal at the bottom of the BC.
--SECOND FORM (Eald'narch solo)--
The amount of time before he gets impatient is more like 30 seconds. There isn't much to say about this form that hasn't already been said, but to summarize/add:
He begins to attack in this form, and does so with high attack speed. Ice Spikes does not seem to proc paralyze. As a RUN, I find myself most vulnerable when he simply attacks constantly without casting or WS'ing.
His spells are limited to Tier II AM, Sleepga II, and Bindga, all with no fast cast. Below 25%, he will gain access to very fast cast -ja spells, which do about 2,000ish damage to non-RUNs. The -ja spells are in addition to his other spells, I often only see him attempt 1 -ja per fight. He often has TP by the time he finishes casting, so be ready with shadows.
His WSs raw damage are not particularly strong, but come with added effects. They are:
- Omega Javelin, AoE physical with added effect petrify. Can be absorbed by Utsusemi. RUNs may want to use Barstone/petrify as a precaution, though with Utsusemi, you likely won't be hit by it in the first place unless he gets lucky.
- Stellar Burst, AoE that adds Silence, powerful Slow (needs erase), and Attack Down. This one is strange, I'm pretty sure it's actually magical because I sometimes get hit by the added effects without losing shadows. Regardless, the effects are not particularly accurate, at least not on a RUN.
- Vortex, AoE that adds Bind and Terror, and resets hate. Can be blocked with Utsusemi, but it is capable of landing even with 3 shadows up. I suggest saving strong hate-building moves (such as Gambit followed by Lunge) in case he gets this move off and resets hate. If he never gets this move off, he won't be teleporting around, making the fight much simpler.
Final Thoughts:
My crew usually brings RNGs along, but we've also used DNC, BLU, and THF. Realistically, for DD's, they only have to watch out for a few things. One is keeping up shadows, to which there is plenty of time unless the kid casts sleepga, in which case it would only hit meleeing DD's. This can be resolved by using Poison Potions or Berserker's Torque/Frenzy Sallet setups. The other is being in range of -ja spells and Bindga. RNG will likely be out of range of the -ja and Bind, while potentially problematic, will not render them useless. Meleeing DD's might have difficulty keeping shadows up in the event of hate reset/AoEs without the help of RUN's Fast Cast (which is available 65% of the time). Hope this post helps some of you figure out ways to handle this BC better, and I can provide more detailed information if there are any questions.
Extra notes for this repost: For support, between BRD/COR/GEO/RDM/whatever it shouldn't be a big deal which you take. This isn't a Scherzo fight and Elegy doesn't offer as much since he only melees in phase 2, at very fast speeds.