Aerbax's Compound

Difficulty:  150+ to survive
Level Restriction:  None? 
Timer:  27 Days
Can be Solo'd?  No, too hard
Rewards:  Empowered Helm of the Perfect Light, Empowered Girth of the Perfect Light, 400M XP (%XP), 35,000 Luminance, Titles, Fortified Mana Forge Key

Aerbax the Virindi Puppet Master finally revealed himself after running amok via his prodigal children proxies.  He is one of Dereth's deadliest foes, but even he can be defeated by a competent group, with a little help from Asheron.

Step 1:  Preparation.  This quest is unique in many ways, chief of which is how your fellowship works.  Only one fellowship may fight Aerbax at a time, so you are limited to 9 people.  You will also have a time limit of one hour in which to defeat him.  If you haven't beaten Aerbax in time, you will be ejected.  In some ways, this quest is a lot like the Colosseum in that respect.  Since you are limited to 9 people, you will need to build the best fellowship you can.  Balance is important.  You will want to have 3 melees and an even balance of mages and melees (4 and 2, 3 and 3).  Your melees need to wear Olthoi Armor or Covenant that has been tinkered to protect against Lightning damage, as Aerbax uses hard-hitting hollow lightning melee damage.  Although some people suggest that everyone on your trip have augmentations to prevent item and spell loss on death, I don't think that's necessary, but if your fellows do drop items when they die, make sure they have plenty of DIs on hand.  Having vitae killers would be nice too, but only if you can get to the NPC who accepts them without using portal magic.

Step 2:  Artificers.  This step is also preparatory and can be done alone well in advance of the quest.  Head to the Obsidian Crater (at the very center of the Obsidian Plain).  The best way to get there is the Dangerous Portal Device, which most mansions have.  There are four small structures in the middle of the crater.  You need to go to the North, East, and West structures.  There you will find a Virindi Artificer.  Kill him.  When you start the fight, it will spawn friends.  Artificers are basically VoD Virindi, so mages should use Singularity Wands and melees and archers should use AR fire or slash.  Each Artificer drops a crystal (and its friends die when it does).  Once you have all three crystals, you are ready for the quest.  

Step 3:  South Gate.  Assemble your fellowship and have everyone use the Dangerous Device until your whole team is in the Obsidian Crater.  Now run to the South Gate and have everyone enter the portals there.  Note that these portals are recallable but not tieable (important for later).  Now run through the South Gate dungeon - it's empty, so you won't have needed to buff yet.  Note that you cannot log off in the Obsidian Crater.  If you need to relog or whatnot, do so inside the South Gate.  It's long!  When you reach the end, you'll find several of Asheron's Diamond Golems and an Emissary.  Once your whole group arrives, go over your instructions (which you'll find below) and then it's buffing time.  Fully buff and bane - even though Aerbax is hollow, he spawns friends who are not (some are!).  Archers should use a fire AR weapon (Composite will be fine) and mages should use CS/CB fire wands.  It would be a good idea to have your Shadowfire and Singularity wands handy too.  Melees should wield a weapon with a good melee defense mod, but damage type doesn't matter.  When everyone is buffed, hand in the three gems to the Emissary and then have everyone use the Device behind the Emissary, which will teleport you into Aerbax's floating castle.

Step 4:  Aerbax.  Aerbax won't go down easily.  Aside from his amazingly painful melee attack, his spells can one-hit you if you aren't careful or lucky.  The basic battle plan is to have your three melees meat shield and everyone else stay sufficiently far away from Aerbax so he can't use his melee attacks.  That extra distance will help in dodging his spells too.  Aerbax's castle is really quite a venue for an epic boss fight, but it also gives your meat shield plenty of bottleneck points to set up.  The castle is set up like a wheel with four spokes.  Those spokes are narrow bridges connecting the four outer platforms with the large central platform.  Have your meat shield set up camp within range of Aerbax on the narrow bridges so that he won't be able to get past you and then have your ranged people light him up.  Sadly, it's not really that simple.  Aerbax has several nasty tricks that will kill people.  First, his magic is very strong.  He uses wave spells that strike multiple times.  These can one-hit you if you are unlucky.  This is especially important for the meat shield - if part of the meat shield collapses because of an unlucky spell, your ranged people will die very quickly.  One of Aerbax's other nasty spells will halve your health.  If you take this debuff, you need to dispel immediately.  Aerbax's second annoying trick is that he will teleport out of fights.  Once you knock off 100k of his health, he will teleport for the first time, then he will teleport every subsequent 200k health.  When he does, he will randomly go to one of the four outer platforms or the central point, INCLUDING the drop point.  The game will announce where he has teleported now.  Another new change is that instead of being able to recover health, each time Aerbax teleports, he will actually respawn as a completely new version.  This is a mixed blessing.  It prevents him bugging back to full health (he will actually appear at full health, but his total health will be lower), but your mages will need to debuff him again.  Always go back through the central platform in case people die.  When you reach Aerbax's new platform, make sure your meat shield is in place before attacking.  Since Aerbax can't regenerate his health past 100% of his new, lower total, you can afford to be a bit more cautious about setting up your meat shield and killing anything that followed you on your run.  Aerbax's third trick is summoning friends.  These friends only spawn on the platforms, so you will generally not have to deal with them except when chasing after Aerbax.  If something followed you out onto the bridge, kill it before fighting Aerbax.  Be especially wary of the Olthoi - they are really nasty and hollow.  Just make sure your melees stay in meat shield mode!  Aerbax also has powerful shield spells that increase his defense to melee, missile, or magic.  When one of these shields is up, that particular attacker will have a hard time landing.  There's nothing you can really do about that except keep slugging away.  Aerbax's last annoying trick is that he can knock (teleport) you off of the castle entirely.  If you get ejected or you die, portal recall back to the South Gate.  Use the portals at the drop to take you back to the end of the dungeon, and then use the device again.  If you need to rebuff, do so by the device.  Since it is possible for Aerbax to teleport to the spawn point platform, make sure you as the leader let any victims know if you are fighting on the south platform.  When Aerbax dies, and he will if your fellowship listens well, he will summon a portal back to Asheron's Emissary on the central platform.  Make sure you recover your corpses first and then hit the portal.

Step 5:  Rewards.  Talk to Asheron's Emissary for your reward.  You will earn up to 1 billion XP for your first success (% XP, capping around level 200) and the Empowered Helm of Perfect Light.  You will also be given the titles Aerbax Slayer and Beacon of Hope.  Sadly the helm does not add any new spells to the Perfect Light set, but it does cast Epic Leadership, Leadership and Mana Conversion Incantations (+45 buffs), and moderates to all four magic schools.  Subsequent victories will earn you up to 400M XP and lower body pieces of Perfect Light armor.  Here's the girth.  The lower body set casts Epic Strength, Coord, and Focus.  As nice as the rewards are, being able to say you defeated Aerbax should be valuable in and of itself!

New in the September 2008 patch is an additional reward.  Speak to the Emissary and you will receive a Fortified Mana Forge key, with which you can open one of the mana forge chests in the capital cities 4 times!