The problem with Smoldering EggSmoldering Egg is two-fold: One, seven counters is a lot of counters to pay off into a simple GuttersnipeGuttersnipe
The Ghost-type's unique shape-shifting mechanic was even introduced into the TCG as a card variant in the Pokmon Platinum Rising Rivals expansion from 2009
Also you drop it for 5, it has haste so you can attack turn 1 and get one of your treasure tokens, I think it's definitely viable
Bronze Reward : 1 March of the Machine pack Silver Reward : 1 March of the Machine pack + 500 gold Gold Reward : 2 March of the Machine packs + 1,000 gold + Change the Equation card style Platinum Reward : 3 March of the Machine packs + 1,000 gold + Change the Equation card style + Nahiris Warcrafting card style Diamond Reward : 4 March of the Machine packs + 1,000 gold + Change the Equation card style card style + Nahiris Warcrafting card style Mythic Reward : 5 March of the Machine packs + 1,000 gold + Change the Equation card style + Nahiris Warcrafting card style
In red you have the pingers such as Cunning Sparkmage as well as Kurkesh, Onakke Ancient, Ghirapur Aether Grid and Quicksmith Rebel that extend the theme into artifacts