Deadmen's Dike - Best we could come up with
Sir RageQuit 30
Description
This quest is absolutely brutal. We didn't hate it, but it can be extremely frustrating to play. You can lose in so many different ways, often unfairly. There are certain 1-2 card combos that can come out of the Encounter deck that will pretty much be "game over". This is true with Shadow cards too. In addition to being able to easily lose from swarms of undead, or high powered enemies, or threat, or location lock, or losing all your allies, you can also lose if you run out of cards in your deck. And there are many mechanics in this quest to force you to throw away many cards from your deck. As such, you need to start with more than 50 cards, but then that dilutes the chances that you get some of your most important cards. So it's a catch-22 of deckbuilding.
After many many playthroughs, and tweaking our decks over and over, we normally come up with decks that beat quests at least 80% of the time, often 90+% of the time. This quest, these two decks were the best we could come up with after trying everything under the sun, and we still won only maybe 30-40% of the time with these decks. So, I think they are as good decks as you could play, but don't be surprised if you lose often, even with these two.
The concept here is that Eleanor exists only to negate the "Dark Sorcery" Treachery card, because this card will usually end your game immediately. Dark Sorcery makes you throw away every ally in play that has a copy in your discard pile. After a few rounds, half your deck will be in your discard pile, so it's likely this card will force you to throw away most of your precious allies. So keep Eleanor up, just to deal with that card. Another option is to try to play just 1 copy of every Ally, but with a 60 card deck, there just aren't enough useful Allies to do that strategy, IMO.
The Glorfindel deck should mulligan for Light of Valinor. Asfaloth is also crucial, as is Warden of Healing. If you don't get those cards fairly soon, you'll be in trouble.
The Tactics player tries to get the usual Tactics attachments into play. This player also needs to get some questers in play, because the threat in the staging area can skyrocket in one round. There's one Treachery that usually adds 4-6 Threat alone, plus a 4 Threat location, and the Fornost Square Location can skyrocket in threat very quickly.
All in all, the only way to win this quest is to get lucky with Encounter draws and Shadow draws. No matter good your board state, you can still lose very quickly with 1-2 unfortunate cards from the Encounter deck.