Edgar, Master Machinist Wizards clearly went out of their way to make Edgar, Master Machinist fair, between the once-per-turn clause and the fact that the artifact it casts enters tapped, but I refuse to believe that we cant crack this like an egg we should probably start with Krark-Clan Ironworks
While we're looking at some of these cards from the aspect of how they fit into certain decks or strategies, Chandra is powerful enough to see in play in multiple different strategies in both maindecks and sideboards
She can bring a piece of equipment from hand or grave into play attached to her, and she comes with a pretty robust set of abilities, too
The last two Modern Horizons sets have seen the printing of three new delve cards: Magmatic Sinkhole, Hogaak, Arisen Necropolis (currently banned in Modern), and Murktide Regent
I doubt the Blizzaga mode ever gets cast though because 6UU is a huge amount of mana