So you wanna see what the final boss of Nightfall looks like *MAJOR SPOILERS*

[Adslahnit]

Well here you go:

http://gw.gamewikis.org/images/b/b7/Abaddon.jpg

Yeppers, it's Abaddon alright! You fight him in the last mission of Nightfall in the Realm of Torment, Abaddon's Gate.

Abaddon is accompanied by several Torment Claws and Graven Monoliths, both of which respawn.

He has three attack skills:

http://gw.gamewikis.org/images/2/27/Corrupt_Power.jpg
Corrupt Power - Skill. All foes take 30 damage 5 times over the next 3 seconds. Each strike also removes one Stance or Enchantment from each foe.

http://gw.gamewikis.org/images/4/42/Words_of_Madness.jpg
Words of Madness - Skill. Target foe takes 120 damage, is knocked down and suffers from dazed for 10 seconds.

http://gw.gamewikis.org/images/e/e6/Earth_Shattering_Blow.jpg
Earth Shattering Blow - Attack. All foes in the area of target take 100 blunt damage and are knocked down. Surrounding foes also take 80 earth damage.

The Graven Monoliths are just like Bladed Aatxes, so Riposte and Deadly Riposte will help take them down. As for Abaddon, he has an uber Armor Level, so Lightbringer's Gaze and lots of Health Degeneration will surely help.

After you beat him, you'll end up in the Throne of Secrets where you can claim your yummy Forgotten end-game items!

[halfthought]

yummy yummy yummy... it was obvous though, so not much of a spoiler

[Sekkira]

Unsure how it was obvious he'd like like that...

[meatloafman]

i wanna know where his mouth is.... get it... abadon.. mouth.... = abadons mouth....

[Almas Darksoul]

From what I've seen of Abaddon, some of this information is wrong.

Abaddon has 4 skills, not 3. The fourth is to summon a Torment claw at a location adjacent to a "foe" (party member). He uses one skill approximately once every 10 seconds.

The skill which he chooses to use is often based on player location. If you are standing next to the monoliths, he uses his fist (Earth Shattering Strike). If you are between the obelisks and the middle path, he usually uses Corrupt Power. If you are standing in the middle lane, he uses his Daze skill (Words of madness). The torment ability is seemingly used randomly, whenever you are not in the middle. He automatically uses the daze skill whenever he is shackled, and as soon as he rises from shackles.

The Graven Monoliths are very different to Attaxes - they have the ability to transform - they are pretty much a level 22 Apocrypha with better (elite) skills. Two spawn at three different points, which must be knocked out. They do NOT count as Servants of Abaddon, despite being his main defenders. Weird oO. You will be familiar with them, you have to fight them in explorables for quite a while before the mission. Note that the Monoliths in the middle section (where his face is) must be killed last, or they will respawn. You get a morale boost every time you activate a set of shackles, so signet use is advised.

Torment claws have a fairly strong attack (60-100 iirc vs 60al), and use Torment Slash, which will deal about 370 damage to a 60al target. It is very easy to dodge for players, as it damages in a short line infront of the Claw (although it will turn to face the target as the cast begins). It hurts a LOT if people gather any DP, so interrupts help a deal. I believe it is a skill, not a spell.

The time it takes you to kill Abaddon is irrelevant for completing the mission itself, but could be considered if you want masters. Everytime he is shackled (by killing the three monolith locations) he will stay there until he has taken a set percentage of damage (100%-->80%-->60%-->40%-->20%-->10%--Dead, IIRC, although it may require fewer steps, starting at 30% lost to begin).

Skillwise: I would recommend you bring condition removal that will help you beat the daze, as that is what causes the most damage. Cautery Signet is probably the best choice, but using a mo with draw conditions and another mo with Extinguish can help. Take rezz signets, on all chars if you can. Warriors are useful as they are not affected badly by daze. Knockdowns are very frequent because of the daze ability, so ward of stability can help.

Note that all of Abaddon's skills affect the entire team, despite the descriptions.