Thanks to a recent COTR episode, I've felt very inspired to think up some ideas for new cards. If any of you are interested, I'd be glad to have some feedback and then maybe get some art and actually mock up some cards.

Spreadsheet

Let me know what you think!

Éomer

Tactics 12 2 3 2 4 Hero Rohan. Noble.

For each point of excess damage dealt by Eomer to an enemy put 1 progress token on the current location.

• I like this guy's effect. Why a cost of 12 for a stat sum of 11? You may think of giving him -1 attack and -2 cost, and allow him to put progress tokens on quests.

Firefoot

Tactics 2 Attachment Mount.

Attach Firefoot to Eomer. Eomer gains the Trample keyword. (trample means any excess damage for one enemy can be put on another enemy)

• Good idea. you may want to make this attachment cost 0, being unique and character specific.

Helmings

• I find them overpowered for their cost. Specially Erkenbrand (stats are too good with that effect, see Faramir for reference), who doesn't need to become a Hero.

Grimbold of Grimslade

Spirit 4 2 2 1 3 Ally Rohan.

Exhaust and discard Grimbold to stop a Hero from leaving play.

• Same as Erkenbrand. 4 2 1 1 2 is more OK.

Banner of the Helmingas*

Tactics 2 Attachment Item. Banner.

Attach to any Rohan character. Exhaust Banner of the Helmingas to choose and ready 1 Helming character.

• I feel this should be Leadership.

Westfold Crofter

Spirit 2 1 1 1 2 Ally Rohan. Helming.

Exhaust and put 1 damage token on Westfold Crofter to prevent an enemy from attacking this phase.

• What about becoming him Lore?

Westfold Scout

Tactics 2 2 1 1 1 Ally Rohan. Helming.

When Westfold Scout is committed to a quest, choose 1 enemy revealed from the encounter deck. If that enemy attacks this round, the defending character gets +2def.

• The effect targets enemies in the staging area right? Should be a Response too. -1 willpower.

Esquire of Rohan

Tactics 2 1 1 1 1 Ally Rohan.

Exhaust Esquire of Rohan to give any Rohan hero +3 def.

Should this be an attachment?

• +2 def. I think he's good as ally.

Other cards seem fine to me.

Éomer* : I agree with karagh but i'd take one of his HP off (instead of ATK which is essential for his ability) and then reduce its cost to 11. And indeed, his power should apply to quests too, it's an 12 (or 11) threat cost hero after all, he has to be powerful.
Banner of Eorl* : I like it
Firefoot* : a cost of 1 would be better suited
Snowmane* : I think it should only do +3WP and 1HP for Theoden, 4 is too much.
Erkenbrand* : with that kind of power it should cost at least 5 or 6, you need to tweak it, not sure how
Westfold Rider : I like it
Hornburg Defender : should cost 3
Westfold Croft : should cost 2
Mail of Edoras : should be Restricted
Grimbold of Grimslade* : pretty good but with Sneak Attack, the abuse is around the corner, you need to prevent that
Spirit of the Hammerhand : OK
Banner of the Helmingas* : I agree with karagh, should be Leadership
Westfold Crofter : Interesting card, but I think it should cost 3
Westfold Scout : I agree with karagh
Esquire of Rohan : I'll go further than karagh and say +1 but I'd add another option so the card would read as

"Action : Exhaust Esquire of Rohan to give any Rohan hero +1DEF
Action : Exhaust and discard Esquire of Rohan to give any Rohan hero +3DEF"

Meriadoc Brandybuck* : I think it'd be more balanced if you make him cost 8 instead of 11, and make his ability function with any character, not just Rohan. Oh and I'd remove his Rohan trait so that as a counterpart he can't be buffed by Rohan effects.
Horn of Scatha* : cost reduction in the hands of Merry should be just 1, it's powerful enough
Stybba* : I like it
Guthlaf* : I like it too
Rider's Banner : Good but i'd make it unique, it's really a strong item
Javelin of the Mark : I like that it's not Restricted but I'd add a limit to 1 per character
Guthwine* : OK
Rider's Spear : OK
Ceorl* : not finished ?

Where is Theoden ?

Thanks for the feedback, guys! No, no Theoden yet. The lads from COTR took part in a meeting with Caleb and kind of spoiled that Theoden is on his way, so I left it alone.

Don't forget the spreadsheet is tabbed so there are other cards as well.

Oh alright !

Let's see those other tabs !

Samwise Gamgee* : It's great !
Bilbo's Song* : I like it
Meriadoc Brandybuck* : Seems alright to me
Farmer Maggot* : Not sure about how efficient it is in game but the rules look okay to me
Wolf
Grip
Fang
Honourary Shirriff* : OK

Passing of the Grey Company : I really like that one but i think it should cost 4
Lord of the Dunedain* : do you go through the deck and then suffle it ?
Barliman's Best : too cheap, should cost 1
Sarn Ford Defender : his stats are a bit too high, -1DEF would be better
Lore of the Rangers : i think this could cost only 3

Dwarf Caravan : absolutely love that one XD

Grima Wormtongue : interesting but as you noted it, it requires that the player uses Theoden AND Gandalf.

When you refer "current location" on for instance Lore of the Rangers or Eomer, you mean active location, right?

Correct!

And with 'Lord of the Dunedain', they have to be in your hand.