Let me just say, that boromir is a card that can go well with a lot of things, which I think is pretty cool. His ability is good when you have a deck that revolves around gondorian cards, and is also great for an intense attack deck so overall, a very good card. This is obviously one of the best cards in the game

Ok, I've recently found a great use for Mablung in my Lothíriel-Éomer deck: ringsdb.com

First, you select your characters for questing and this happens simultaneously: quest with Éomer and Lothíriel and then trigger three responses: first put Mablung into play via Lothíriel. Then trigger Mablung's response that moves an enemy that was engaged with you to the staging area. Finally, trigger Éomer's questing response. If you manage to play a few weapons on him, he will swing for 6-7. And +5 engagement cost often means that the enemy won't engage you back this round.

With Visionary Leadership and Steward of Gondor, these three characters will quest for 9, which definitely isn't bad.

Poor Óin . . . he's really been done a nasty. This is literally his only rendition and it sucks. It feels almost as if he starts with a handicap and you need to pass the 5 dwarf restriction just to get him back to normal.

He isn't the most prominent of Thorin's company, nor an important figure in LotR, but still.

Seems like it's the trend for the dwarf archetype: mediocre unique characters.

This card can be fantastic in a multi-sphere deck if you want to e.g. change the target for the Steward of Gondor mid game. If you played a lot of the cards from one sphere, but you lack resources to play cards from another sphere, pull Steward back to your hand with Bartering and play it on another hero.

You can also make use of it in a multiplayer game as a way of resource smoothing: if another resource-rich player plays an attachment on one of your characters, you can play Bartering, give him back the attachment and then play one of your own attachments at a discount.

If you own older sets, it also works BRILLIANTLY with Beregond - you can play a 2-cost attachment on him for free, use Bartering, play some other attachment on another hero at a discount and then play the initial 2-cost attachment on Beregond for free again. There, you just created 2 resources out of thin air.

It's a very useful card if you think about it. It may not be flashy at first sight, but I had great success with it. @ThimYorke has also featured one of its key uses in his review.

Not cheap, but he's got a hero stats and a hero ability. Throw Valiant Determination and A Burning Brand on him for a great quester/defender - even in Battle and Siege quests. It's a bit much, but if you wanted to go for a voltron Gildor thing and you can manage to get it set up then Sneak Attack Gildor in during the planning phase and slap Sword-thain on to him to officially make him a hero. Then he won't leave play at the end of the phase (since he's no longer an ally) and you've got yourself another hero to gain resources and throw hero-only attachments on.