Counterfeits often show: muddy dots misaligned patterns colors bleeding in ways the rosette pattern doesnt This is one of the more reliable non-destructive checks if you have a loupe or phone macro lens
There aren't enough targets in most decks for it to be wortwhile in the main deck
Five mana isn't a steep cost, either
7 Ygra, Eater Of All Clamaity Has Come One of the most interesting Calamities in Bloomburrow, Ygra, Eater of All has a fascinating approach to Magics creatures, seeing all of them as food for it to eat and, in turn, makes all creatures in play, yours and your opponents, Food artifacts as well as their other types
Think about how the card actually works: the first time you cast it, you get a Shock for two mana