Hi, my name is crankypanda and I started playing late last season. This is a yeti list that I have been tweaking and experimenting with constantly. I am currently somewhere around masters #15 with this deck. Clearly, it is based off of the list from isomorphic (mad props to him for developing the concept. His deck can be found in the link below:
http://eternalwarcry.com/decks/details/8A1AlVxh4Fg/ynstybly-yyyy
Iso does a good job of laying out the concept, so I will just explain the reasoning behind my card changes. I am not suggesting that my list is superior, but this version has worked better for my game process.
1) Eilyn's Invtervention (3): The original list iso posted did not include any copies of this card, but now he runs one. My masters games have been heavily tilted toward 3-color Icaria pile, AP mid, and a few other decks. I actually ran 2 Eilyn's and 2 Kaleb's for a while as an answer to harsh rule, but I've cut the Kaleb's to experiment with Mirror Image (discussed below). In pile or grenadins matchups, this card is critical for negating Hailstorm, Madness, Assembly Line, Slay (AP mid or Icaria black), et cetera. Against (J) midrange, you need an answer to Enforcer and Unseen Commando (Permafrost-ing this is not ideal); sometimes 4 Torch is not enough. It also lets you conserve your torches for Champion of Glory, which can also be trouble in the early game. The worst matchups for this card are time decks, but you can still achieve value from a mass chump block or countering Torch.
2) Levitate (2): I have become a big fan of this card. I like the cycle so much I would almost advocate for testing Katana (with Windflyer?) in this deck. I think cycle improves the consistency of your Wump boards and bond combos. Because it is instant, you can use this for an unexpected flying block. Obviously, the card is strong on both Thundrock and Fearless to guarantee their effect or just push damage over a stagnant board.
3) Mirror Image (2): This card is some dank fun. Shout out to Ahorn for suggesting it to me. Obviously you can go even on value by copying an important creature like Wump, Thundrock, or Fury lethals. The ideal useage is to combo it with Unstable Form to copy something huge. A common (poor) outcome of Unstable is that you pull a low-statted minion with a Summon effect. Mirror Image triggers all Summon effects, which is also applicable to Cinder Yeti at times.
4) Iceberg Warchief (0): This card has been underwhelming for me. I often like to discard Power through Slope Sergeant after I hit 4 in favor of keeping more gas. It often feels more like a win-more card than rally with a body. Its statline is absolutely terrible when your board is light, which is common against pile. If I ever hit 6 Power to summon it and play a spell during the same turn, I've often lost anyway because that is too much power and not enough gas.
5) Power base (-Granite Waystone): I think this deck runs so little red Power that this card did not pay off for me. The main thing is actually that 10 Sigil's is the (ideal) minimum for playing 4 seats. I cut Waystone to get up to 9, which is close enough. The trade off is that drones make a good discard for Slope, but they have been absolutely horrible when I summon them. The deck is more consistent at playing on curve with this Power base in my experience.
Last comment: I cannot decide between 4 Snowcrust Yeti or 2 and 2 Windflyer. On one hand, having 3 health on Windflyer (with Wump) is a big tipping point for blocking against aggro. Flying obviously provides good poke. Snowcrust trades poorly, but benefits from costing 1 and is truly godlike against removal pile. I think it depends on what you encounter more on ladder.
Cheers!