Three: Ethereal Conjurer
Ethereal Conjurer is a newer card, and one that raised quite a fuss for its rarity. You may have noticed that every card we’ve mentioned so far is a common. That isn’t because we aren’t including other rarities, it’s because the best Mage cards for arena all happen to be commons. Ethereal Conjurer kept this rolling, assuring that Mages would have good cards in their decks. Ethereal Conjurer is an insane card in all aspects. It is a very strong tempo play, while also providing a ton of value. Not only do you get a card from it, you get to choose from three, meaning you can take exactly what you need for the situation. Because it only chooses from Mage spells, getting what you want is common. Also Mage spells are universally fairly strong.
Ethereal Conjurer is the reason Tempo Mage now stands a chance against Control decks in late game. And that’s referring to constructed play. If the card has that much potential in constructed, imagine its strength in arena. Once again because of its rarity, you can easily get duplicates as well. With Ethereal Conjurer you always have the spell you need, and a body to boot.