This is the list I used to climb to Rank 4, three days into the month, and then to Rank 3 a few days later. The trick is to draw Sling often.
It's nothing you haven't seen before, and the bulk of this list is copied from Serus, with the only notable twists being zero Torch and 3x Tamarys.
Tamarys is a great multipurpose card. X/1 units are everywhere and she hits a lot of them, she pops aegis, and she triggers the draw half of sling a turn earlier than you could otherwise. She also helps a lot with threat density, which is something that older versions of the list had trouble with thanks to running removal in those slots instead.
Torch is gone because I found I didn't miss it. Hailstorm, Huntress, and Kenna mean I have plenty of ways to hit small-medium units, and I find I want to plunder for Primal a lot more than for Fire.
The sideboard shows the experimental changes. 2 Wisdom of the Elders have come out for 2x Campfire Watchman. He triggers sling draw even earlier, sponges hits vs aggro, and is a nice base for Huntress. The downside is that he's pretty bad without sling and turns on some otherwise dead removal like Suffocate.
Sudden Schism out for Replication Cell. I'm experimenting with the market here and there, and these two cards fill similar but distinct purposes. Schism is a quick copy of your best unit, while Replication Cell can make a game go out of control after it gets rolling. It's definitely a card that works better in long games and only in long games. It might be correct to run both of these and cut Rejection instead - that card is aimed at Harsh Rule decks and the occasional At Any Cost deck, but Rule-based control is a rarity on ladder these days, and this deck is a lot worse at holding up mana without Wisdom of the Elders.