Forbidden Shaping: A lot of people wrote off this card as bad because it doesn't get you as much stats as an average minion of the cost you play it for, but it adds a ton of flexibility to the deck, helping to make up for all the situational cards like nova, death, cabal, allowing you to curve out a lot better. It also helps that it's both an early minion if you need one against aggro, and a lategame threat against control. Generally should be played on turns where your alternative is weak, or when you're floating a lot of mana and can use another minion. Lategame the best cost to use it on is 8.
Shadow Word: Pain: Another card that is very good situationally. With Shaping helping the curve, there's more space to run removal cards like this. Especially good vs Shaman (Totem Golem, Trogg, etc).
Shifting Shade: Performed well as a 1-of, helps give the deck more stuff to do mid and late game without losing too many stats immediately.
The main matchups I've seen a lot of so far:
9-1 against this so far, I think I can pretty safely say this is a favored matchup. The deck has a lot of early game to deal with their early game, pain helps a lot as well, and you have more taunts than most decks do right now. Death on the 4 mana 7/7 helps a lot as well. Don't be afraid to Shaping for 0 or 1 mana if you really need to.
5-0 so far, also feels like a favored matchup. I've won so far mainly by taking board early, and keeping it with removal. Pain and Death both have several good targets in this matchup. Remember to play around Master of Evo and Fire Elemental if you can.
3-1 so far, not sure but on paper this shouldn't be a favored matchup. Theoretically, druid should be able to keep board early game with ramp and the good midrange minions, and it did do that pretty well. The games I won were mostly through slowly taking back board and running the druid out of cards, but it's hard to tell how the matchup plays out usually because they had wild growth on 2 every game. Consider keeping Death as well, they have a lot of good targets for it.
Mulligans: The general strategy is to find a good curve of minions, especially dragon synergy ones. Keeping Twilight Guardians or Azure Drakes to guarantee those go off is often good, keeping power word shield is good usually, and keeping pain is good against decks with a lot of early game. Not sure what the strategy is for keeping shaping, right now I'm leaning towards only keeping it if you're expecting a slow deck, or already have a good early curve because it isn't really the ideal play on turn 1 or 2.