@vaughnbros Vigor can break openers and this card does not. Instead, it completely dominates the mid/late game at little opportunity cost compared to filling your deck with green spells. I personally am much more afraid of the latter, especially considering its synergy in Oath and Dredge decks.
This is a ridiculous ability on a body that has upside when it gets removed (and it will). Unfortunately, it's too slow against PO which may be enough of a hurdle to prevent much testing.
On the other hand, builds are currently going through a massive metamorphosis thanks to the new Karn so a few copies may slip into lists.