pokemon card shiny mew EX Captured in a crystal UMU - Rumors are this

(So much so that now most of the cheap acceleration we make costs at least two mana.) You can start powering out your threats quicker than your opponent, putting you at a sizable advantage

Firebrand Archer and Kessig Flamebreather are even better, since they count any non-Creature spell

Creatures your opponents control lose hexproof and cant have or gain hexproof

Its possible that players are noticing this uptick in copy cards and devising strategies around it

The second best is Tarmogoyf, which gets enormous here thanks to the enablers we need for Crack the Earth - Chromatic Star and Oath of Nissa

Probably too slow for Constructed, but if we are using it, were probably using it with Gishath, Suns Avatar or some other source of mana cheating