This is my first deck published, using only one core and all expansions. It's meant to be a defensive, Gondor/Ent deck in multiplayer, gain a ton of resources, then transition into high attack power and moderate questing if needed. Either Beregond or Denethor make good use of Gondorian Shield. Steward of Gondor can go on either Denethor or Boromir with Gondorian Fire.
The bulk of the allies are ents, because the heroes are strong enough to survive a few turns without worrying about their drawback. Faramir will pump up your allies' willpower to not be useless, but you will typically use it on your partners.
Your starting had will ideally have Shield and Steward or another resource acceleration card. An early Treebeard will help get the other ents on the table. Your card draw is pretty limited to Rod of the Steward, so I included Legolas in the sideboard if you don't care about theme. Also, you are relying on Gandalf and your friends for threat reduction, especially with Boromir raising it.
Mid to late game, you want Armored Destrier and The Day's Rising on Beregond, along with a Shield. He can now defend twice, get rid of a shadow card and gain an extra resource per turn. Boromir Has Gondorian Fire, and you can slide him resources from Denethor or an Errand-rider. Captain of Gondor is also pretty good on him. You can give him ranged with Dúnedain Cache so he can help out others.
The sideboard has Legolas for draw, Secret Vigil for some threat reduction, and In Service of the Steward to give resources to non-Gondor heroes your friends may be playing.