The Dark Council

After you kill Thanaton, you get to make some conversation choices:

If you saved Darth Achelon, you can tell him to kill Thanaton's supporters, collect artifacts and rituals, or "serve the people".

Your force ghost friends show up too, and you have the option of keeping them around or freeing them. I forced them all to be bound to me, and didn't make any pact in blood. I got the opportunity to ask them I could help them find peace, but Kalatosh Zavros told me, "No, you are too dark. You are doomed to our same fate and therefore cannot save us." I'm DS 4; maybe LS inquisitors get a different option? If you force them to stay, Andru and Ergast get pissed off. If you tell them they're free, Horak-Mul would rather stay with you than be forgotten on Hoth.

Then you get to talk to your followers, and you tell them your next goals are to find more power, to defend the Empire against the Republic, or to take over the Sith Empire.

Afterward, you can talk to Khem Val to start The Escape if you have enough reputation with him.

I'm Corruption spec (heal) and I tried doing this quest with Talos as the companion and ran out of force when I got Thanaton to 50% so I ran outside to reset the fight. I tried using Xalek since I've really kept his gear up to date and was able to down him on the next try. I had him in Force Barrier stance and I just made sure I put down revivification where Xalek was tanking and used Innvervate as much as I could to proc a free Consumption. I also had to pop Recklessness and both my Relics which helped out a lot. Xalek didn't take too much damage except during Force Storm. I just put him as passive for this part and just stayed out of Force Storm. Rinse and repeat. Oh and I also disrupted his heals. Didn't interrupt the other ones.

**Why did I get a downrate for this? This is how I was able to down him after trying other ways. SMH**

Note, the last part "The Dark Council" where you are directed to Travel to Dromund Kass:

You MUST use your starship to get there - don't take the shuttle from the Fleet, etc. Otherwise the mission won't update properly.

When it updates, it should read "Go to Darth Thanaton's Meditation Chambers"

What worked for me: (level 50 Lightning Sorcerer)

* Even though I never used him before, Talos Drelik did the trick. Just not having to worry about healing was key.
* Constantly move to avoid zones.
* Keep up Affliction and Crushing Darkness as much as possible.
* Using Static Barrier on cooldown.
* Interrupt every healing (revivification) Thanaton casts.

The fight will take awhile, but shouldn't be a problem.

I did this quest as a level 49 0/8/32 Assassin. I started out with Xalek and failed hard. Per comments here I switched to Talos. I have never really quested with him so most of his gear were items he started with. First phase of the fight used interrupts as much as possible, Talos had no problem keeping me healed. Second phase of the fight Thanaton starts spam casting Force Storm. At this point he cannot be controlled, but force storm is pretty easy to avoid if you keep moving. After he gets bored with Force Storm he becomes controllable again, so back to interrupting as needed. Talos and I were at full health at this point from avoiding Force Storm so the end of the fight was pretty easy.

TL:DR Use Talos, avoid Force Storm, Win

Soloable at Level 46 (when 50s are no longer Red-Con) Assassin, Madness tree.

Companion was Talos, gear was Oranges with 40-44 mods, 100-108 armor rating.

Used Dark Charge, guarded Talos, and basically used Discharge, Shock, Death Field, and Creeping Terror. When I got the occasional Trash on him, I used Crushing Darkness insta-cast procs. Took around 15 minutes, but didn't have to pop a medpack, Deflection, or even Channel the Force.

Always keep moving, don't stand in his Death Field or Affliction. I try to Jolt every Revitalization, or Overload if Jolts on cooldown. If nothing works, I run clear to the opposite end of the room to force him to move out of his heal circle to be in range of me.

I am specced healer, and have leveled up with Khem.
On certain boss level sorcerer mobs he has gone down like a rock, and I've had to put him on passive just to move out of Force Storms. But against Thanaton, I could just let him stand in one place while i dealt damage to the boss. Threw the occasional Static Barrier and Innervate (for a free Consumption) on Khem.

Save your interrupts for when he uses his heal (Revivification).

Spoilers!

If your lightside, I hold the title of pure you can save all 4 of the ghosts and set them free into the force. I know most of you are dark so figured id put that out there for those curious =D

Korriban
- Of Mind and Matter – Level 3
- The Plight of the Acolyte – Level 4
- A Little Knowledge – Level 5
- The Secret of Tulak Hord – Level 7
- Martial Law – Level 8
- A Map to the Future – Level 11 [Khem Val & Lightsaber]
- Go to Dromund Kaas – Level 11

Dromund Kaas
- Onwards to Dromund Kaas – Level 9
- At the Foot of the Colossus – Level 11
- Dismantling the Machine – Level 13
- Giant Killer – Level 14
- In the Hall of Traitors – Level 15 [Spaceship & Start Chapter 1]

Balmorra
- Plans – Level 15
- Scientific Inquiry – Level 16
- Extraction – Level 17
- The Path to Power – Level 18
- Into the Pit – Level 19

Nar Shaddaa
- The Call - Level 20
- The Prophet Arrives - Level 20
OR The Krayt Gang - Level 21
OR Curing the Rot - Level 21
- Manufacturing Miracles - Level 21
- The Big Show - Level 22
- The Final Act - Level 23
- Preparations - Level 24 [Kallig's Countenance]

Tatoonie
- Andronikos Revel - Level 24
- The Pirate and The Girl - Level 25
- Vengance - Level 26
- Into the Dune Sea [Andronikos Revel] - Level 27

Alderaan
- The Secrets of the Jedi - Level 28
- A Woman Scorned - Level 29
- Secret Rendezvous - Level 30
- In the Halls of Elysium - Level 31
- Service Rewarded - Level 30
- Inheritance - Level 32
- Legacy - Level 32
- Taking Control [End Chapter 1] - Level 32
- Sith Hierarchy - Level 32

Taris
- The Padawan - Level 32
- Laying the Trap - Level 33
- Means of Persuasion - Level 34
- The Apprentice [Ashara Zavros] - Level 35

Quesh
- Thanathon Strikes Back - Level 36

Hoth
- Scouring the Wastes - Level 37
- Bitter Rivalries - Level 37
- Into the Assassin Temple - Level 38
- The Fallen Dreadnought - Level 39
- Conflagration - Level 41
- Battles to be Won [Talos Drellik & End Chapter 2] - Level 41

Belsavis
- The Price of Power - Level 41
- Prison Break - Level 42
- Strange Science - Level 42
- Ghosts in the Walls - Level 43
- Mother - Level 43

Voss
- Building a Power Base - Level 44
- Visions and Visionaries - Level 44
- Secrets of the Force - Level 45
- Necessary Sacrifice - Level 46
- The Ritual - Level 47
- Testing [Xalek] - Level 47

Correlia
- First Strike - Level 47
- Blood and Fire - Level 48
- Fatal Blow - Level 49
- The Duel - Level 50
- The Dark Council - Level 50

- The Escape - Level 50
- Looking Ahead - Level 50

Did as 47 Assassin tank. Main companion has been Andronikos. So, his gear was up to date, minus implants/relic. This fight was a complete joke.

Interrupt what you can, focus revivification though, and stay out of his AoE. Didn't get below 80% and I didn't need to blow any of my CD's.
Was really hoping for more of a challenge.

As far as the ending, I'm rather upset one of the DC members actually killed him and I didn't get to deliver the final blow.

Edit: Fixed as of 1.0.1 on 12/27/11

As of release the problems with this quest bugging out remain. For some characters the quest bugs in Thanaton's meditation chamber on DK and will not allow the completion of the cutscene showing the resolution of the story. Personally I have tried relogging, reloading the UI (ctrl+U x2), and dropping the quest to no avail (Note that if you try dropping it you'll have to go back to Korriban and do the hard part again). It is currently speculated that it is only bugged for people who receive the title Darth Nox in the previous cutscene on Korriban. Regardless it means that some people are unable to complete the culmination of their class quest and can not receive their "Darth" title.

On an absolutely related note, while you are on the quest and unable to turn it in, the problematic cutscene in question will erroneously begin under strange circumstances. For example, I was attempting to exit my ship once and Khem'Val appeared from a top down view against a backdrop of stars as though I were on a space mission. He then began giving all the dialogue of the cutscene while floating in space. It was illuminating but still didn't give me my title.

Just want to corroborate this comment. I tried and failed as a Deception Assassin several times with Khem Val as my companion. Then I switched to (a seemingly undergeared) Talos and got him on the first try.

Did this last night, L49 Assassin 02/31/7. Tried w/ Xalek blowing cooldowns, interrupting, not knowing Thanaton goes immune to controls at some point for about a minute. Vanished a few times to reset. Then I did it with my homeboy, Talos, and we rocked that &*!@. Never went below 40%. The split between you and Talos keeps the aoe damage down to a minimum. Sometimes Thanaton targets him, sometimes he targets you, but not nearly as harmful when its 2 melee together. I interrupted but not nearly as necessary or stressful. Your choice of companion can really make and/or break a fight. Talos=EZ Mode.

PS - I was Dark Side V, got the Darth Nox title, but didn't experience the bug that has been noted previously.

Gayest most useless un-heroic quest in the *!@#ing game.

This game sucks so much cock.

I didnt have one bit of "fun" doing this quest.