The new LTR card [[Last March of the Ents]] is an excellent Green "Ok I'm winning now" curve-topper. I doubt it'll see much play in Modern or anything (though I'll be happy to be proven wrong!) but for Commander/Historic Brawl where you can actually cast an 8 mana spell, fantastic.
I'm a huge fan of [[Verdant Rejuvenation]] which is unfortunately Arena-only (though it would have been so easy to make the paper version [[Majestic Genesis]] on par by making it actually reveal until you get X nonland permanents). Last March of the Ents seems like an excellent sidegrade/possible upgrade depending on the deck.
I'm thinking I'll run it in [[Tiamat]]. Cast Tiamat, then next turn you draw seven and can drop all the fetched Dragons in one turn without them being able to be countered. Any other decks that would be particularly synergistic, besides just high-toughness?
Scholar of the Lost Trove ?
It would let you play Last March for one mana less as well as provide a five toughness creature, which isn't a bad deal. You just have to find a way to get Last March into your graveyard.
Aha, that makes more sense than Sphinx of Lost Truths. That's not bad, yeah.
Might be overkill, but you could cast Last March, use it to put Scholar on the battlefield, then Scholar triggers and you get to replay Last March for free. Pretty sweet.