The card hasn't seen a ton of play, largely because the variety of potions makes it too inconsistent, but as players finally got around to experimenting it became abundantly clear that something was amiss.
One Chinese team logged 1419 samples and found that the Priest potion hadn't been selected even once.
At the time, Game Designer Dean Ayala provided a potential explanation, "'Potions' isn't a concept we have in code/script. They have to be added manually. Dragonfire was a last minute addition to 'Potions' so it's likely we just didn't add it onto the list."
So if you're feeling adventurous or are just a fan of the Arena, feel free to use the card again, its peak power level just got much, much higher.