Designed for multiplayer scenarios with emphasis on sturdy allies and potent heroes.
The deck aires a bit more towards the thematic, perhaps even suffering accusations that it just wants to play Fangorn in a deck. The Last Alliance enables more affordable costs on pricier allies and some helpful synergies in exchange for cards like the sorely missed Warden of Healing, or higher end allies generally exclusive to Vilya decks. The starting hand is fairly important for this deck, ideally wanting Vilya (or Master of the Forge) with Imladris Stargazer, and a copy of Self Preservation (or Lembas). The latter enables Treebeard to utilize his ability quite liberally without concern of a bad encounter effect preemptively removing him from play due to overindulgence.
Ent allies are the defensive backbone of the deck. Since they generally incentivize being damaged, using them sporadically for light attacks is advisable, before combining Ent Draught with Self Preservation on some allies with more staying power to provide enhanced sustainability. This combination still struggles a bit with heavy hitters, so utilizing the strong attackers in the deck to remove offensive-centric enemies posthaste is highly advisable. Treebeard ideally eventually receives the Light of Valinor (courtesy of Alliance), Self Preservation, Magic Ring,and Lembas to maximize his ability's potency and his utility. The main usages of The Last Alliance are on Entmoot which is an exquisite synergy to retrieve swathes of allies, the aforementioned Light of Valinor on Treebeard so that he can take full advantage of his bolstered stats, and if neither of those are available, Booming Ent/Leaflock to make use of damaged Noldor Allies. Overall, the usages of The Last Alliance are less explicit than with say Dáin Ironfoot or Boromir, but they enable some fun opportunities unique to this combination. The deck would be well paired with another deck containing decent spread replenishment such as Warden of Healing or a Silvan themed deck, or one that specializes in defense or questing to compliment the versatility of this deck.