This is going to be a Hogaak Summer level Affinity upgrade...
This is such a ridiculous setup I can't help but think the rest of MSH is just going to be a skinned over MH4, or at least I am praying it is so that anyone outside of Affinity can see new tools.
Ok, so the insanity comes from the new Ironheart, Cleaver Champion she herself is a 5 mana 1 Blue Improvise card, trivial to turn 1, then she gives Improvise to ALL NON-CREATURE SPELLS. So in a more or less standard Emissary Affinity list she enables ditching Kappa Cannoneer, already one of the strongest cards in the format, for a turn 2 Ugin, Endstone, or the also new card Ten Rings and then literally never run out of gas, ever, not a once...
Or simply play a free Tezzeret, Cruel Captain, convert one drop, to one drop, to one drop, ad infinitum, then Tezzeret with all the free one drops and the zero drops can just ult and start animating their guys with turn 2 emblems, this is too gross.
Affinity was already tier-0, so why are they doing this to us?
Cards:
https://scryfall.com/card/msh/60/ironheart-clever-champion
https://scryfall.com/card/tdm/1/ugin-eye-of-the-storms
https://scryfall.com/card/eoe/240/the-endstone
https://scryfall.com/card/msh/251/the-ten-ring
https://scryfall.com/card/eoe/2/tezzeret-cruel-captain