The Idea:

This deck began as a way to merge all of my favorite aggro all-stars into one comprehensive deck. Throughout Beta and AL, I predominantly mained Sparkmage and Flamecaller. But as the card/avatar pool grew, so did my interest in other avatars, and realistically, I didn't want to have to obtain cards for 5-6 different decks. So the question became, what if Imposter could be everything I wanted and more? And so far, I have not be disappointed. The avatar's flexibility based on the scenario at hand has proven extraordinary, and if you can keep your face protected, you can accrue so much value in a short amount of time. And in the end, we have a deck that's more aggro/mid-range due to the cost requirements, but is extremely fun to pilot and effective at the same time.

The Avatars:

Below is the reasoning behind adding the Avatars I have and a brief explanation of their role(s) in the deck:

Archimago - To recycle value spells such as Grapple Shot, Blink, Fade, Infiltrate, and Whirling Blades for additional use.
Avatar of Air - The ability to move minions/myself to more advantageous positions on the board work both offensively and defensively. Paired with Wuthering Heights, you can send allied/enemy minions on quite the trip.
Enchantress - You say, but you run no Enchantments? That's correct! This is to combat other's enchantments so you can turn them into minions and displace/attack them for movement/removal - Thanks for this idea GoldenEagleCards as this pick was originally Elementalist to smooth out any early threshold issues.
Flamecaller - Generation of value over time. Many minion picks require heavy Fire threshold which further benefit this choice when a blast of damage is needed. If your opponent loses sight of this, it can definitely be unexpected.
Interrogator - Minion picks are in alignment to work well with interrogator. You can setup good turns with Phase Assassin, Sturmgeist, Hotwheel, etc. that can generate quite a bit of value in the form of additional damage or card advantage.
Ironclad - Strictly for death's door. This pick makes you immune to dying from common sources such as Zap or a ping from Ring of Morrigan. Amulet of Niniane works double-duty here (as it can also prevent you from losing your mask in the early game) to keep you protected if you're in danger.
Pathfinder - The ideal pick for turn 2-3, This way you can continue to draw spells for your turn and simply flip the top site to maintain card advantage. I intentionally left our Tri-sites (initially added for threshold consistency) to prevent any risk of an accidental dead flip.
Sorcerer - The status quo and a great mid-late game pick for drawing additional cards when sites become irrelevant.
Sparkmage - Much like Fire minions, I've gone heavy on air threshold to make this a viable pick. Paired with Blink and previous avatar movement from Pathfinder and AoA, this can provide a nice shock of damage when needed.
Witch - Mainly a pick to ensure guaranteed damage, if you're 1-2 damage short of DD'ing an opponent, this is the solution that can drive it home. And to a much lesser extent, a good way to stave off an overly aggressive BM.

Ideal Opening Hands:

Spells:

Here you're looking for a good blend of minions/spells/ and any artifacts you can get your hands on, as those are the most powerful cards in the deck - Ring of Morrigan and Amulet of Niniane can be absolutely backbreaking. The Ring being self-explanatory, while Amulet of Niniane will ensure longer runs under a single mask as often your opponent will try to snub you early on with a lightning bolt, magic missiles, etc.

Great minion hits are Vile imps for early board presence/maintenance, Redcap Powries requiring answering and take the heat off your avatar temporarily, Stygian Archers can quickly maintain/flip board ownership, Cerberus in Chains is extra protection from your avatar being hit, All of these These can help keep you in form until you hit a critical mass

ideal opener magic is that which will enable your minions, Grapple Shots and Blinks (replaces itself) can help inch your minions inch closer to your opponent's Avatar. They may not think much of it while in Pathfinder form, but after you've accrued enough value, you can quickly swap into Interrogator for 2-3 direct Avatar hit turns, each instance of damage requiring your opponent to either let you draw or pay 3 life respectively.

Sites:

Ideally, you'll like to see at least one Tower (Dark, Gothic, Lone) in your opener to try and hit 3 mana on turn 2. This will enable you to immediately transform into Pathfinder to start accruing early card advantage by drawing spells while flipping your top site vs. drawing them.

Otherwise you're looking for sites to enable your spells with their accompanying threshold as requirements will continue to steepen into Air/Fire to enable Sparkmage and Flamecaller. Other great sites to see early are Wuthering Heights and Observatory. The free movement Wuthering Heights provides means you can start to send some of your charge minions further into enemy territory (which once again reinforces Interrogator), and Observatory will give you a clue as to what's coming down the pipeline and to better plan your next mask. In addition to these, any sites considered a direct counter your opponent's goals - Accursed Tower (anti-ward), Vindictive Nation (anti-site destruction), Funeral Pyre (anti-cemetery), etc. are all solid.

...Additional info yet to come as this page is a WIP!

A Wolf In Sheep's Clothing

@jlcoverdale