Morningtide , Shadowmoor , and Eventide have the most scarecrows among all Magic sets
Enigma Sphinx Enigma Sphinx has a hefty mana cost, but who pays full price for artifacts anyway
Saga Creatures are in an odd space where theyre better Sagas, but weaker creatures
Experimental Frenzy should at least see sideboard play in every non-Izzet Red Aggro deck with room to be built around in maindecks as well
In other formats, Izzet Charm, Expressive Iteration, etc
There are about a million 2/1s for two mana with some sort of upside that are playable, not just in Standard but in Modern as well, which means Naban, Dean of Iterationwhile restrictive in another way (only working with Wizards)is much easier to build around than Panharmonicon