This format is going to be aggressive, and this card is going to effortlessly win a lot of games
Purphoros, God of the Forge My favorite aspect of Purphoros, God of the Forge is the ticking clock element it adds to the game for your opponents
Mox Opal is a clear frontrunner with Grinding Breach already in ban discussion territory
Fallen Empires gave us creatures with a shroud ability that could be activated with mana, and that was followed by Autumn Willow, a Homelands chase card (I know, that sounds funny to me too) with a static shroud ability pre-keyworded as cannot be the target of spells of effects. Magic replaced this with the slightly less stultifying hexproof, which is still just as obnoxious when youre sitting across the table from it
Bifur, Melodic Rider also has Storied and a matching effect for an enduring story, which is to trigger all abilities from Dwarf creatures an additional time