Is it a fish deck? Not exactly. Control? Not like that. Aggro? Not quite. Is it a nasty, merciless, hate-filled deck designed to leave your opponent with two hands tied behind their back? Most definitely.
If you like Inquisition of Kozilek and watching Control cry, then this might be the deck for you.
Heart of the deck:
This deck revolves around hand disruption and exiling things into oblivion.
The main engine card of the deck is Oona's Blackguard, supplemented by Metallic Mimic. Oona's Prowler, Thoughtseize, and Inquisition of Kozilek round out the hand disruption package. Ideally, you want to get Blackguard out Turn 2, but if not, then either Prowler or Mimic. Of the three options, Mimic is the slowest, but it helps you build boardstate and prep your creatures for Blackguard procs. It also lets the Blackguard proc itself if the Mimic is still around when you finally get one on the field.
Then, for eternal banishment, we have Surgical Extraction, Extirpate, Earwig Squad, and Ashiok, Nightmare Weaver. Surgical and Extirpate work beautifully off Turn 1 Thoughtseizes or Inquisitions, and cleanup really starts hurting by Turn 3. Extirpate is in side to allow for greater Turn 1 flexibility (Surgical off a Thoughtseize for Game 1), and works great sided in against both control and decks that like to be cheeky with Emrakul reanimations and such. Earwig Squad is brutal because it's not limited to what you can target in their graveyard. Granted, it won't hit all copies or cards in their hand, but it can cripple their plans pretty succinctly. Especially if your opponent is having mana or color issues with their lands (or Tron pieces absent), and you wipe out that last color or Tron piece they needed. And Ashiok, Nightmare Weaver is, well, Ashiok. You don't really need him for his other abilities, but they are nice. Especially if you manage to snag a Death's Shadow or Tarmogoyf.
For our removal package, we run Fatal Push, Go for the Throat, and Dismember. With two playsets of fetches, you can almost always guarantee Fatal having its 4 cmc spot removal range active. Go for the Throat is nice for avoiding Spellskite, and since this deck struggles against affinity anyways, having it mainboard gives you three easy slots to side out against affinity. Dismember is nice because Fatal can't kill everything (like Tasigur, the Golden Fang from Grixis decks), and sometimes you just don't have the open mana for a Go for the Throat.
Card draw engines are either our Sygg, River Cutthroat or Sign in Blood. Although we do run two Watery Grave, Sign in Blood gives us offensive capabilities over cards like Serum Visions, Ponder, or Brainstorm.
This deck offers a lot of versatility, both in its approach and playstyle. It can be more control-oriented, or it can just spam the board with creatures that are more than mildly inconvenient for your opponent. It runs enough spot removal that it just kills whatever your creatures don't. And flying and unblockable creatures like Inkfathom Infiltrator mean that you're going to have a higher probability of resolving prowl costs, probably the best "cheating" method of casting the deck runs.
However, this versatility sacrifices consistency. When the deck goes off well and needs to repeat that process game 2, it often doesn't and just lolz its brains out at you. I'm currently working on the theory craft for a better version, adding in more Ashioks, bringing in a playset of Bitterblossoms, and adjusting the main and side boards appropriately. Final note: what this deck wants, what it really needs, is a black rogue version of Thalia's Lieutenant