The forum activity on Carn Dum has all but died out. However, all along I have been playing the quest over and over to confidently say that I have mastered it. I built a set of two handed decks and tweaked them for the quest. The final version of the decks beat the quest in 4 out of 5 games. The decks do not use hero Gandalf or Glorfindel or Outlands, or any of the commonly dismissed "broken" cards. I also did not use the trap strategy, which kept enemies in the staging area to drain the encounter deck with undiscarded shadow cards. I wanted my wins to avoid "cheap tricks". I personally have nothing against such tactics, but it was a fun challenge to avoid them. Here I will include a guide to explain how to beat the quest.
First, a lot of people complained that this quest was stupidly difficult and made the game unfun. I was one of the people who argued against these complainers, but after my extensive play experience I must admit I see their point. This quest is ultimately unsatisfying, in my opinion, not because it is hard, per say, but because the entire strategy to winning is focused on the first two turns. At least this was true in two handed (solo is much much easier). By the end, if I did not have solid control after 2 turns I would just resign because there was no point. As a result, any strategy that could not be executed until turn 3 was a total non starter. This meant that over 90% of cards and strategies were immediately unplayable.
Two handed is brutal because you can see 2 or more (with surge) treachery cards with the sorcery trait, in a single quest phase. This could result in many game ending consequences including massive threat increase or multiple unexpected attacks with severe shadow effects. The key to the quest is having many defenders and having shadow cancelation. This is particularly true in the second stage of the quest when the boss can end up attacking the first player 4 times in the same round. In order to get as many defenders ready as possible a general rule us to stay in the first stage as long as possible (kind of like the strategy for beating battle at Carrock). Side quests are a good way to delay while still advancing you setup, although my final decklists did not actually include many side quests.
The mvp, and main focus of my team's strategy was Gildor with burning brand and cloak of lorien. His high defense and shadow cancelation were essential to victory. I would boost his defense and grant sentinel with Arwen and then ready him with Cirdan and Narya. Once this combo is setup, the scenario is basically defeated. My first deck was entirely dedicated to achieving this combo on turn 1 or 2 with card draw, elf stone and/or To the Sea! To the Sea! to get him into play at little or no cost.
My second deck was a modified variation on Seastan's Very Good Reinforcements deck. It generated a lot of resources for both decks (legacy of numenor) and used sneak attack and reinforcements to fuel a very good tale to get high power allies like Gimli and Legolas into play on turn 1 or 2. It also used descendent of thorondor, Longbeard orc slayer (3 copies in deck) and Gandalf to do direct damage against enemies in staging.
In most games, by the end of turn 2, I would have Gildor set up, along with 2 or 3 other high power allies. There would be no enemies or locations in play (other than the boss), and I would have plenty of resources and cards. I would then slow play a few rounds to get more and more allies before advancing to stage 2. I would assume 4 attacks against 1st player before finally being able to win.
I hope this is helpful for those who struggle with the quest. I will include my decklists below shortly (probably tomorrow). Thanks.
Edited by DukeWellington