Just because I dont see a particular card being played at my LGS, despite believing its actually quite good, doesnt mean it isnt played by every single player at the LGS down the road
Mutated Cultist: Um, hello
3 Some tribes may need support by other ways of design, or rather you can tailor some of them to help support archetypes in your cube (my soldiers can support generic aggro, token, heroic, and probably some other things as well)
As do multiple forms of Niv-Mizzet
Hitting both artifacts and creatures is great and can really stall decks that rely on treasures
If all that sounds too niche, remember you can play Metamorphic Alteration on opposing creatures to make them worse, copying a 1/1 token or whatever else is lying around