Reversal Mage

Strategy
Reversal Mage can theoretically fit into various types of decks, but it so far has seen most success in aggressive decks as a way to penalize big mana cost plays and pressure the opponent further with a 3/3 body alongside the effect. At the right moment, this kind of tempo swing can absolutely keep the game in your favor where the opponent might otherwise have stabilized.

With Counterspell, this card remains one of the few cards where the effect explicitly only works on initiative. As it comes with a body, it's arguably better as an aggressive tool than a Counterspell. Disruption Mage had somewhat similar design, but its 1 ATK isn't something you can realistically use to clock your opponent outside of Tunneler Worm decks. The nerf to increase Disruption Mage's cost and change it to a 1/1 turned it further into a Counterspell kind of effect and less of an aggressive tool.

Update Changes

 * Originally costed 5 mana instead of 4.

Reversal Mage was updated on the free stat buff week 36. It now costs 4 instead of 5. This seemingly small change rather quickly gave rise of Ashgerdy Tempo decks and remains one of the key cards in identifying the archetype.