I wanted to build a deck featuring Denethor and sons, and I specifically wanted it to be tri-sphere, because of all the different cards I could tap into.
Most of the time, you probably won't have that much to pay for with Denethor himself, but he can always give a resource to either son (let's face it, he;s going to give it Boromir, even if Faramir can make better use of it). Most of the time, Boromir will be doing the heavy lifting, but Faramir has his uses and they are many: card draw, healing (hopefully he will have the resources to get repeat use out of the Wardens in a single turn), getting round condition attachments, are all nice toolbox things he adds to the deck, whilst Boromir is off killing things.
Being a 53-card deck, the Miners of the Iron Hills can be dropped for quests with no Condition attachments
The main problem this deck seems to have is with questing, so not that strong in true solo. I'd be interested to know how other people would improve it, whilst sticking with the overall theme (I rejected the idea of Ents as they made no narrative sense , however powerful they might be).