Hearthpwn

With Secret Mage seeing virtually no play (much less moderately competitive play), this deck was built around that archetype and the play style it brings with it. Mage has many of the most powerful and simply funnest secrets in the game, and a key element of this deck's play style is the mind games. Opponents will often make sub-optimal plays to avoid Mirror Entity, Counterspell, and so on, and this deck allows you to capitalize on those sub-optimal plays.

This is a pseudo-aggro/mid-range deck. While this deck is more about board control, it has the ability to fluidly switch play styles according to the opponent and situation. It allows you to rush the opponent and control the game, depending on who you are playing against and what you need it to do. It takes experience to know when it is best to control the board and when it is best to rush face, but generally speaking it is better to keep control. Unless you think you have immediate lethal, always keep the damage spells for minions, whether you are playing aggro or not.

Ethereal Arcanist and Ethereal Conjurer win games. They are the core of the deck. Ethereal Arcanist will always be a raw 5/5 for 4, but he becomes absolutely monstrous when left unchecked. Your multitude of earlier minions ensures the opponent probably dumped most of his removal, and Arcanist's constantly expanding attack and health make it difficult for the opponent to constrain.

Ethereal Conjurer, on the other hand, can very easily turn around games by allowing you to pick the card you need to level the field when you are behind. His high attack makes him monstrous if the opponent already wasted his cheap removal on your early minions; if Conjurer can survive even one turn, the huge damage you can do is often too much for the opponent to bounce back from.

Mulligans

- Keep Water Elemental against weapon classes (including Hunter); otherwise, there are no class-specific mulligans.
- Always mulligan for your low mana drops: Mana Wyrm, Unstable Portal, Mad Scientist, Sorcerer's Apprentice.
- Never keep Kirin Tor Mage unless you have a secret. Never keep a secret unless you have Kirin Tor Mage, except if you have Duplicate or Ice Block and have Ethereal Arcanist. Remember, Arcanist wins games.

Card Swaps

For a bit more control focus, consider trying Flamewaker and Dr. Boom. I currently have neither of these, and one of the boons to this deck is its relatively cheap cost, but if you have them then I fully recommend trying them. If you're encountering many zoo decks, try a Flamestrike.

Cards to consider replacing include Duplicate, one Counterspell, and one Water Elemental. I do not recommend replacing both Duplicate and one of the Counterspells; this deck is very secret focused and the large number of secrets are required to play mindgames with the opponent. One Unstable Portal can also be replaced, but I keep them for synergy with Mana Wyrm and Sorcerer's Apprentice.

Finally, play around with the secrets! One Counterspell could be removed for a second Mirror Entity; Ice Block could be replaced with Vaporize. With full-in Secret Mages being so rare, opponents will get frustrated with this very easily. The synergy between the secret mind games and the fluidity of the aggro/mid-range play styles create a lot of options both with deck editing and manipulating your games.

I hope you like it! Secret Mage has little representation in our meta, and I'd love to see that change.