While not a new hero I have only come to discover the possibilities for this great hero. Some people still rather the ally for Ent decks but this particular Ent could have a deck of his own making.
This hero has heft stats and a large threat cost. So in general you might not want to add a bunch more threat to the pool without some answers but with the ability to add +5 to Willpower and Attack, a good defense and a nice hit point value this hero covers it all.
Decks designed to heal would best be suited for Lore Treebeard. If able, healing up to 5 (or more) damage a round would get the most out of his turns. Adding Ent draught or healing between triggering the damage will help get every ounce of whatever you need out of this treefolk. Running an eleven kin will allow the use of Lembas to help and ready Treebeard for a second use. Not sure about why this Ent would be eating this bread but it works!
Wellinghall Preserver and Booming Ent can help and get things moving. Add in a few Warden of Healing and Lore of Imladris to seal up any healing holes and you will have a bunch of fun with this beast.
But don't be hasty! While adding in Elrond or Core Glorfindel might seems like a good idea, make sure you have an answer for all that threat. Personally, I would rather take the hit and use either Spirit Glorfindel or 2 other low threat Lore heroes but the choice is yours.
Use Lore Hero Treebeard in your next deck, you will not be disappointed when he is stomping orcs destroying locations.