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Hunted Nightmare Art by Antonio Jose Manzanedo

Mono Black Obosh Aggro Deck Guide

Who am I?

My name is Mark Gabriele, and I am an SCG Tour Grinder and avid Arena player. My absolute favorite deck in Standard is all flavors of Mono-Colored aggro decks, and I recently took Aaron Barich’s Mono Black Obosh deck to Mythic. If you have any questions about the deck, feel free to email me at or message me on Twitter at @gabriele_mark!

What is Standard Mono Black Obosh Aggro?

Mono black Obosh is a deck full of one and three drop creatures, supplemented by the most powerful removal and discard available in the format. These features allow the deck to have hyper aggressive draws which can end the game by turn four, or to tempo out opponents by playing more efficiently than them up the curve. The entire deck is designed to take advantage of Obosh, the Preypiercer, an insane damage output engine who makes combat steps a nightmare for the opponent. Being mono color allows the deck to take advantage of a rock-solid manabase, and one that features the best land in standard, Castle Locthwain. Mono Black Obosh was designed by Aaron Barich as an improvement upon the RB Obosh deck which Jammernaut won the Online Weekly Championship with this past week.

Obosh. the Preypiercer Art by Daarken
Obosh. the Preypiercer Art by Daarken

The List:

Mono Black Obosh Aggro by RuneclawBarich – #54 Mythic – April 2020 Season

[sd_deck deck=”pFBTVxn7n”]

Why no Cat Oven Combo?

One of the most noticeable things about this list is that it doesn’t play Cauldron Familiar and Witch's Oven. The reason for this is that, while Cat Oven is powerful, it’s not necessarily aggressive. When you look at the effect that having Cauldron Familiar and Witch’s Oven has on a game, one of the most notable is how difficult it is for the opponent to attack you. But why would an aggressive deck be worried about being attacked? It wouldn’t. This problem is amplified by our deck not having any card selection, and both Witch’s Oven and Cauldron Familiar being particularly weak on their own.

In addition, Cat Oven derives a lot of strength from the parts surrounding it; like Mayhem Devil. But to put those cards in our deck, we have to play red. For the time being, the mana bases for Rakdos in standard are…not great. So, assuming we are interested in being mono colored for a rock solid mana base, and we are aggressive, both Cauldron Familiar and Witch’s Oven are out of place.

Card-By-Card Analysis

Main Deck

Gutterbones – The only 2 power one drop in the deck, and the one you want to play on turn one if you can. I’ve been surprised by how little I returned it from the graveyard; in the early game your mana is better spent elsewhere, and in the late game you usually either aren’t triggering it or are spending your mana in better places, like Whisper Squad or Castle Lochthwain activations. Most opponents are disinclined to kill Gutter B even when they can, so keep that in mind when deciding whether they have removal in hand or not.

Knight of the Ebon Legion – KEL is back and ready to beat face like it’s summer 2019. The activated ability on this little homie puts in a lot of work even when you don’t activate it, as it allows it to attack freely into groups of creatures and threaten to kill any of them that block. As a result, the first order of business on a lot of turns is attacking with KEL, and then playing out other creatures postcombat.


Serrated Scorpion – This is probably the weakest one drop creature in the deck, but it does its job providing some moderate sweeper protection and making combat really hard on the opponent when they are low on life. You often get into spots with this deck where the only way your opponent can get out of it is a sweeper, and being able to play scorpion in those situations is really powerful. It’s worth noting that these scorpions deal damage when they die, rather than making your opponent lose life, so it is doubled by Obosh.


Whisper Squad – My opinion of this card has gone up every time I’ve drawn it, and I’m pretty firmly in the “This card is messed up” camp now. It’s a self contained curve, giving you something to do on turn two even if your hand is stocked up on only three drops. It works incredibly well with Heraldic Banner, giving you an outlet for extra mana and fetching extra bodies to pump. It’s a fantastic topdeck when both you and your opponent are out of resources. It’s more or less impossible to kill if you play it with two mana open. It gives you a squad to chill with while in quarantine. This card is everything you could want.

Shadowspear – This card isn’t exceptional by any means, and it gets boarded out a lot, but it’s upside is high enough to warrant a couple maindeck copies. This deck is well equipped (get it?)  to take advantage of equipment, as the normal downside of “They kill all your stuff and you’re left with a blank” is heavily mitigated by the resiliency of cards like Whisper Squad. This thing attached to a Rotting Regisaur or pumped Knight of the Ebon Legion swings races in a big way, and opponents won’t play around sudden bursts of lifegain. Try to hold this in your hand until the turn of the big swing.

Rotting Regisaur –

Hunted NightmareThis card being in the maindeck is a pretty clear indicator of what we’re trying to beat. Fires and Rec have trouble with this card, as it Matrix-dodges most of their sweepers and removal. The downside is significant against decks with a lot of small creatures, but a 4 / 5 Menace for three is worth the potential downside game one, and you can always side it out.

Murderous Rider – This card is solid of course, as has been proven over the past six months of standard. Both halves prove useful in this deck, and having a catch-all that answers every companion ensures that this card will be useful in just about every matchup.

Drill Bit – One of the secret stars of the deck. Save this card for the turn before what you’re scared of would be cast (usually sweepers). Having a playset of these main and two Duresses postboard gives you pretty good odds of being able to preemptively answer your opponent’s gameplan, but this plan only works when supplemented with ample pressure. 

Heraldic Banner – I initially dismissed this card as too cute (does Rotting Regisaur really need an eighth point of power?) but boy, was I wrong. Because of the mass of one drops required to take advantage of Obosh in an aggro deck, the play of “Turn three Banner into a one-drop” comes up quite often. In addition, this deck is very mana hungry; at a minimum, you have a five drop you want to cast every game, and you have plenty of mana sinks besides that. For sideboarding purposes, I treat this more as a land than a spell, and as such am reluctant to ever cut many copies.

Castle Locthwain – A completely outrageous card. One of the best arguments you can make for playing Mono Black is literally just “you get to play Castle Locthwain and be confident that you’ll get to take full advantage of it”. This deck’s mana is pulled in a lot of different directions, so drawing a card with Castle is usually one of multiple options, but having it as an option at all is powerful.

Mobilized District – The argument for this card is mostly “Why not?”. We play 19 swamps, which gives us a 98.6% chance of having a Castle Locthwain enter untapped on turn two. If we were to cut District for a twentieth swamp, the odds would go up to 99.2%, a 0.6 percent increase. I think that District will help you more than that 0.6% will, but it’s marginal, and I wouldn’t blame anyone for cutting it for another Swamp.

Swamp –


Obosh, the Preypiercer – A lot is being written and said about the power level of companions, so I’ll leave it at this; I think starting every game with Pot of Greed in my hand is powerful, and I will be doing it as long as they let me.

Disfigure – Your options for removal are limited because of Obosh’s restriction (it took me five minutes to figure out why the deck didn’t play Heartless Act), and Disfigure is good enough against enough of the field to warrant it’s inclusion here. Playing four of these bad boys allows you to transform into pseudo-control postboard against other aggro decks, which is a sweet thing to have access to. 

Duress – Perhaps the quintessential sideboard card in modern Magic. We top out at 2 copies here because the most hand disruption you want in any matchup is six, because any more than that starts eating too much into our ability to pressure the opponent. Still, we want this against any deck where sweepers are a concern. Before bringing Duress in, ask yourself what you are trying to hit with it. If what you are trying to hit encompasses too much of the opponent’s deck, it’s functionally closer to a Raven’s Crime than a Thoughtseize. This is not where you want to be, because you are allowing your opponent to exchange 1 for 1 with you for no mana; in fact, YOU’RE spending mana to do it. For example, I am not bringing in Duress to hit a cycling card out of the cycling deck, because I am spending mana and a card to hit a card that just does the same thing as every other card in my opponent’s deck, and not really keeping them off of anything in the process. I am bringing in Duress against Jeskai Fires, because I am much more worried about Deafening Clarion and Shatter the Sky than I am of the rest of their cards, and am happy to 1 for 1 with either of those cards.

Cry of the Carnarium – The ol’ Whisper Squad/Cry of the Carnarium deck. This card may seem out of place at first, but it’s a key part of your plan to board into a control deck against other aggressively-slanted decks, who don’t really have the same option. As long as you sideboard with minimizing the downside in mind, you should be fine, as it will usually be much worse for your opponent than it is for you.

Pharika’s Libation – This card earned its inclusion more by being the only enchantment removal in black than by being excellent on rate. It’s good enough against Reclamation and Fires, and can clean out a creature in a pinch. Don’t be afraid to board it in because it is rarely dead, but don’t expect it to do too much heavy lifting, and always be mindful of your curve.


Cavalier of Night – A hammer against aggro decks, and a good curve topper when you board into control.

Sideboard Guide

Lurrus Sacrifice Decks+4 Disfigure
+4 Cry of the Carnarium
+2 Cavalier of Night 
-4 Gutterbones
-4 Rotting Regisaur
-2 Serrated Scorpion
Keruga Fires+2 Duress
+2 Pharika’s Libation
-2 Shadowspear
-2 Murderous Rider
Bant Yorion Ramp+2 Duress-2 Shadowspear
Temur Reclamation+2 Duress
+2 Pharika’s Libation
-2 Shadowspear
-2 Murderous Rider
Cycling Decks+4 Disfigure
+4 Cry of the Carnarium
-2 Shadowspear
-4 Drill Bit
-2 Gutterbones
Mutate Decks+2 Pharika’s Libation -2 Shadowspear 
Obosh Decks+4 Cry of the Carnarium
+4 Disfigure 
-4 Gutterbones
-4 Serrated Scorpion

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