Sepulcher of Nightmares

Difficulty:  100+ for rewards, 150+ for the Gate, Gate is too hard to solo
Level Restriction:  55+ for 3 rewards, 150+ to complete
Timer:  21 Days on XP items, 7 Days on Rewards
Can be Solo'd?  Yes
Rewards:  Two 10% XP items, Caliginous Aegis, Circle of Raven Might, Mitts of the Hunter, 3 MMD Notes

The Cult of the Raven Hand is committed to the Darkness.  Now their Grand Archon has appeared on Singularity Caul and his minions have taken up residence in several ruined castles.  What's worse, new shadowy beasts have appeared on Caul.  What are those Ravenists up to?

Step 1:  Preparation.  The vast majority of this quest takes place in Singularity Caul, so you need to be flagged to participate.  Ideally, you will have Caul Recall too.  You need to be level 55 to get to the Caul, but I strongly recommend against anyone below level 100 trying this, even in a group.  The Ravenist encampments are well guarded, so try to field a strong group.  When your group is assembled, Recall the Caul and start buffing.  You will primarily be fighting Humans and Shadows, but you may need to kill off a Caul critter or two.  Frost and Slashing weapons should be sufficient.  Bane and Protect against all damage types.  When your team is buffed, it's time to storm the castles!

Step 2:  Raven Castles.  There are 3 castles in southern Caul that you will need to invade.  Each is protected by a large number of Ravenist Humans, highest level Shadows, an Archon of the Cult, and a Shadowy monster.  The first castle is just north of the Caul drop, located at 96.5, 95.  Approach from the west and clear as you go.  Inside this castle are Archon Traesis and the Margul Xaa Xiil.  Kill them both and loot a Caliginous Aegis from the Archon and a Twilight Fragment from the Margul.  The Archon drops less shields than the Margul drops Fragments, so you may need to kill him more than once.  Once everyone has both items, jump off the east face of the castle and run to 94.3, 93.4.  Clear your way to the castle by approaching to the southwest.  This complex is actually two small towers, one containing a Greater Void Lord and the other containing Archon Greis.  The Void Lord drops a Raven Fragment and the Archon drops the Circle of Raven Might (a crown).  Again, you may need to kill the Archon twice, which won't be an issue.  When everyone has their items, Caul Recall back to the drop.  The final complex is at 95, 98.2 to the NW of the drop.  This final complex is a downed Advocate Tower and is protected by Archon Ingfall and a Greater Panumbral Horror - a really great looking Shadow Grievver.  The Horror drops an Iniquitous Fragment and the Archon drops Mitts of the Hunter.  When you have all 6 items, it's time to leave the Caul.  Combine all 3 fragments and then take the resulting seal to Sarkin Killcrance in Wei Jhou.  If you are below level 150, he will accept the Seal and give you 10% of your level.  However, if you are 150 or higher, he will return the seal to you, in addition to giving you the XP.  If you are below 150, your quest is now finished.

Step 3:  Nightmare Gate.  You will need a small army to clear this dungeon, so if you started with only a handful of 150+s, keep your seal for another time.  If you do have the numbers, then take your seal to the Nightmare Gate in the northern regions of the Caul (90.0N, 93.4W).  The Gate is atop a tall lighthouse in the middle of a large castle complex swarming with the nastiest of enemies.  Your best bet is to run into the castle, up the lighthouse, and give the seal to the gate as fast as you can.  If you have a large group, you could try clearing the area, but that would be exceptionally dangerous.  Have your team run in and up one at a time, but let everyone know that their corpses are basically unrecoverable should they die.  You must also GIVE the seal to the gate, not use it (unlike the other Gates).  The dungeon itself is appropriately named - it is crawling with Raven Conscripts, VoD-style Shadows, and plenty of Marguls.  The only time I visited the dungeon, I only had one companion and although we didn't die, we didn't make much headway.  Deep inside, you will find the remnants of a Soul Crystal similar to that of the Hopeslayer.  Evidently, a demonic being that used to be the Ruschk Gladiator Grael was imprisoned inside by the Dericost, in the hope of harnessing his dark powers for use against their enemies.  You will also find two tomes - the High Archon's journal and a Dericost tome.  Take the Dericost tome to Zaikhal for translation and then return the books to Sarkin Killcrance in Wei Jhou.  He will reward you with another 10% of your level!

Optional Step 4:  Raven Aegis.  The Caliginous Aegis is a potent shield!  However, if you prefer, you may alter it into a magic-absorbing Aegis.  You will need to visit the Lugian Excavation and recover a sample of High-Grade Chorizite.  Then have your chunk refined at the Beach Fort.  Now head to Martine's Retreat in Rithwic and find Leandra.  Give her your refined ore and she will give you a potion to add to your Aegis.  When you do, the shield will lose its armor level and it will no longer cast Strength VI on you.  The Aegis will gain a magic absorbing property and retain the two moderate cantrips and Invuln VI, however, making it much more useful than the typical Sanguinary Aegis.  While the unimbued Aegis is fully giveable, adding the chorizite will add a character wield requirement.  

Step 5:  Rewards.  Aside from the lore and experience, you will recover the Caliginous or Raven Aegis shield, the Circle of Raven Might crown, and the Mitts of the Hunter gauntlets.  If you have some time to spare, you can also hunt the Caul for a Void Lord.  He drops a special spell scroll called Curse of Raven Might.  This spell is a Lifebolt Ring!  It drains half your health and uses that health to generate a ring that does 2x the amount of health drained to any target within range.  Ouch!