Chain of Smog The original idea behind Chain of Smog seems to be that youd fire it off and enter into a game of chicken with your opponent to see how far each of you were willing to go before you were both hellbent
Authentication is near the top of that list
It doesn't matter where your commander is (or commanders are, if you have more than one because of the partner ability or similar)
Izzet spellslingers are a dime a dozen, and while the payoff here is Roothas ability to turn those into big Elemental creatures, this means the early game features relatively minor gains
While these lands were flex "spells" you could freely slot in your deck, more importantly these lands created a whole deck archetype in combination with multiple legendary creatures and (the rotating) Slogurk, the Overslime
Wait no longer, Commander fans: Commander 2019 is here