Ahhhh, Green, finally. Red was OK, but that's just my bias.
Aether Herder: In battlecruiser we don't have one drop mana dorks, and that means this is likely the weakest of this cycle.
Aetherwind Basker: Reads Mythic for sure since you can have lots of Energy to make this really, really big.
Aetherstream Leopard: solid in Limited and even in Constructed. If it's the only creature on the field, it can be a nice four hit early game.
Aid from the Cowl: Seems like too much mana for only one card. Something has to leave for this trigger to happen. In some cases, what you get will be really good. I would try it and see what I get. I guess I need to play it to know how good it is.
Druid of the Cowl: Welcome to battlecruiser.
Greenwheel Liberator: Will work well with White since you can have something leave and then come back. Otherwise, you are losing something for this effect.
Greenbelt Rampager: Very interesting. You can cast it for G on purpose to recycle mana into Energy. I want to play this bad.
Heroic Intervention: A good way to have access to Hexproof now that it has been taken out of creatures.
Hidden Herbalists: Solid in White/Green. Something would have to die for you to get the extra mana, and it's otherwise a bear. I like it a lot. It's a really good uncommon.
Lifecraft Awakening: A great way to recycle late game mana. Another great uncommon.
Lifecraft Cavalry: Solid in Limited.
Highspire Infusion: The Energy bonus is very good. A needed battle trick in Green.
Lifecrafter's Gift: Great uncommon. You can get a lot of counters out of this in the right deck.
Monstrous Onslaught: Compare with Polukranos, World Eater, a Mythic Rare from Theros: (2GG 5/5 Creature XXG: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.) When Polukranos, World Eater becomes monstrous, it deals X damage divided as you choose among any number of target creatures your opponents control. Each of those creatures deals damage equal to its power to Polukranos.) Seems like a solid uncommon.
Maulfist Revolutionary: I want to play this bad. That counter can be a Poison counter, or a Planeswalker loyalty counter.
Narnam Renegade: Very good uncommon. Vanilla it would be a really good common. As an uncommon, it is even better, of course.
Natural Obsolescence: In many situations, it will be as effective as Naturalize. I can't find a card like it issued to date. Nice addition!
Prey Upon: Hello, old friend.
Peema Aether-Seer: That can be a lot of Energy, especially outside of Standard. Great uncommon.
Ridgescale Tusker: Solid uncommon. That can be a lot of counters. It reads better than many junk rares.
Rishkar, Peema Renegade: Great way to have a mountain of Green mana. I am sold. It's not the strongest in the cycle, more in the middle.
Scrounging Bandar: Solid in Limited. It allows you to up the count of creatures with counters on them by one.
Rishkar's Expertise: I love this card. In my Green Devotion casual Modern deck, I can have an eight power creature on the board often enough that I can draw eight cards off of this. I like it a lot.
Silkweaver Elite: In Bant (White/Blue/Green), I can have something leave the battlefield, cast this, then have this leave the battlefield, then have something else leave the battlefield. That way, I can draw two cards from this. How doable is that? I want to find out.
Unbridled Growth: a variant of Utopia Sprawl (Enchant Forest As Utopia Sprawl enters the battlefield, choose a color. Whenever enchanted Forest is tapped for mana, its controller adds one mana of the chosen color to his or her mana pool (in addition to the mana the land produces). The advantage is that you can enchant any land, and the disadvantage is that you only get one mana out of that land. With Utopia Sprawl, you double your mana.