A Wizard Who Knows Better

While Saruman managed to ruin Isengard's relations with both Rohan and the Ents, corrupting poor Gríma in the process, imagine what could have been if only a different wizard had been in charge of Orthanc. Someone who knows better. Someone like Gandalf.

Strategy

As the intro suggests, this is an Isengard + Rohan + Ent deck. The strategy is to use Gríma and Keys of Orthanc for resource acceleration and resource smoothing, effectively allowing you to get 2 resources for the price of 1 threat each round. This helps you quickly pump out an army of Ents, so you can get out of the early game faster (which is notoriously hard for Ent decks).

Mulligan for Keys of Orthanc first and Narya second. All your Ents already have insane stats, but with Narya they get boosted even further and you can ready them at will! This makes combat almost trivial (for example, Derndingle Warrior can defend for 6 twice, Treebeard can attack for 5 twice, etc.).

Card draw is provided through Entmoot, Daeron's Runes and Expert Treasure-hunter (which is guaranteed to succeed thanks to Gandalf). Gandalf's effect also effectively doubles as card draw if you play the top card of your deck with him.

While the deck starts out with only 29 threat, Gríma's Doomed effect may cause it to increase faster than you'd like. Luckily, we run both Woodmen's Clearing and Secret Vigil for cheap and effective threat reduction.

Early game

Like most Ent decks, this deck is quite vulnerable in the early game. That is where Éowyn comes in: Not only does she quest for 4 right off the bat, you can also use her effect turn 1 to get rid of any nasty enemy the scenario manages to throw at you. This helps swing the momentum of the game immediately in your favor, as that first turn is crucial for getting you up and running.

(Of course, if it's not necessary, it's better to preserve Éowyn's effect until later; but definitely don't be afraid to use it early on to get a head start.)

You should try to always play Keys of Orthanc first turn to get your resource acceleration going. The only times I would not is if the scenario punishes you for reaching 30 threat (e.g. in Journey Along the Anduin the Hill Troll has 30 engagement cost). Don't play Narya until you have 2 allies out to get the most out of it. That being said, it it doesn't hurt to mulligan for it, just to be sure you have it as soon as you need it.

Sideboard

The sideboard contains some situational options:

• Ioreth is good against quests with heavy archery, but also against quests that have you start out engaged with a weak enemy, since she can heal Gandalf after he takes an undefended hit.
• Pippin is a good 2-cost 2 ally against quests that require strong questing from turn 1. You could also consider including other such allies like Mablung or Robin Smallburrow, but they are less thematic.
• Ent Draught can help against scenarios where you need to repeatedly defend attacks from a high enemy. However, even without it, Derndingle Warrior supported by Narya and Warden of Healing can already defend an 8 enemy and survive.
• Deep Knowledge adds more early game card draw to get the deck going, but it also accelerates your threat even further. Against scenarios that don't punish threat too harshly, this may be an option.
• The Wizards's Voice is another quite thematic Doomed card that can help you get through a troublesome early game, at the cost of accelerating your threat.
• Flame of Anor is also a good card to strengthen your early game against scenarios that start out quite brutally. It helps you get an additional use out of Gandalf with a big boost to boot.