Let's count them down: The "gets -1/-1 for each card in your hand" makes it really difficult to play in a control deck (which generally wants a hand full of answers), and a control deck is the most obvious home for the blue mythic flier
This Umbreon is outstanding but the back has a tiny bit of whitening which netted this the 9 grade
These special illustration style treatments for both Greninja ex and Kingdra ex are beyond gorgeous, and actually my two favorite from the entire set
But the second ability makes it shine in zombie-infested decks, like black token decks tend to be
For a Magic card, really just a small rectangle of cardboard, the demand is even more subject to change, at least theoretically
Named Elder Dragon Highlander (or EDH), the creator's idea was to promote long and epic games where unusual and less played cards had a chance to shine