Oh man.
Oh man, did my favorite deck archetype get support. Not only did a sweet transform card that tons of people appear to not take seriously enough get printed, but then I heard everyone talking about Helios. In Feln control. ...And then you make her body real enough to tussle with big dorks. (You also dodge Turn to Seed, as a bonus.)
This deck is not
fully optimized, particularly the Market (except the Pelt, you really only need the one), but it's good enough that I can post this hot nonsense and spread my love for transforming cards around Eternal. It's a decent Gauntlet deck, too.
To start off, even the bottom of the curve has stuff going on.
Wildgrowth Druid is surprisingly obnoxious for opponents to deal with, especially in conjunction with
Equivocate and
Desert Alchemist, who is delightful for consistency. Cheerful Shepard seems like a strange choice, but she's great to turn into a 3 drop, and provides 2 blockers for fast and aggressive decks.
And then there's
Reshape, which is the card that makes everything just delightful. Every single card here is good to transform, sans maybe Great Valley Smuggler or a Wildgrowth Druid that's going off, but if you're to that point, you're probably winning. Targeting the enemy board can sometimes be good too, if you really need to dismantle an opposing big board. This deck is made to survive to getting to six Time influence, so make sure you use it to make the most impactful board possible (or deny opposing Turn to Seeds from the opposing side).
The rest, outside of the (somewhat hastily built) Market is
Wisdom of the Elders for that last little bit of card draw the deck desires,
Turn to Seed to remove big threats, and fantastic transform targets, along with
Unstable Form, which is itself, and just a good time.