Mono Shadow Gauntlet Grinder (Dark Frontier)

This is the first deck that I have found to be both fast and very consistent at Masters gauntlet post Dark Frontier.

Spells:

3x Dark Return - Get your best unit back, and synergizes with Blackhall Warleader.

4x Spiteful Strike - An excellent combat trick, helps race against aggro and blow out multi blocks by the AI. You will sometimes win otherwise losing games just thanks to using this as a lifegain spell. You can trick the AI go wide decks by using this defensively on a blocker. Very versatile card.

4x Cabal Standard - One of the benefits of being mono shadow, we run very few depleted power so can run a full complement of this excellent combat trick.

2x Suffocate - Aggro decks are a thing, as are 1/4 endurance flying lifesteal multifaction 4 drops.

3x Annihilate - Solid two cost, fast removal.

4x Desecrate - Two cost removal that can hit multifaction units like Reality Warden. The life loss is almost always offset by the lifesteal this deck has.

4x Vara's Favor - Kills so many x/1s. You can also do things like attack with an Argenport Instigator into a 4/4 Champion of Wisdom and trade off before it becomes a 6/6 flying that your Annihilate in hand can't deal with. Pops Aegis.

4x Cull the Deck - Play this card as late as possible when you are trying to dig for a specific answer or a threat late. Helps a ton with consistency.

Units:

4x Argenport Instigator - Perhaps the best two drop in the game for gauntlet considering all the go wide decks and the amount of damage this can deal when the AI attempts a multiblock. Great statline.

4x Blackhall Warleader - Another excellent two drop that scales well if unanswered and synergizes well with Dark Return. I usually try to play Warleader before Instigator if I have both in the opening hand, but this depends on board state of course,

4x Rhysta, Acantha's Herald - This may actually be the best card in the deck. While lousy against aggro (can't block), she is often able to pressure well with at least one hit, and the AI will trade off cards like Twinbrood Sauropod. Getting power number four on time as often as possible is great, as we want to ideally start curving into our powerful late game threats. Late game, the Shadow sigil can be market fodder.

4x Vara, Vengeance-Seeker - Fairly compelling reason to play a Shadow deck, no explanation needed.

2x Shadowlands Tyrant - Fantastic Gauntlet five drop, it can pick apart a board state and help you come back from behind against aggro. We have another copy in the market.

4x Tasbu, the Forbidden - We run a total of six five drops. Tasbu has all 4 in the main to maximize the chance of getting that sweet warp value. The card is pretty good, and can help you grind out the AI.

4x Kerendon Merchant - The 1 health is unfortunate, but deadly is a relevant keyword against the AI midrange decks, and markets are good.

Market:

Shadow Sigil - We don't want to miss power drops against the AI, that's the main way this deck loses.

Madness - This card can be game winning if you grab a big blocker, particularly if it happened to have lifesteal. You can also sometimes trick the AI into blocking its own unit for a nice two for one.

Nullblade - Occasionally you grab it to smash face, but it's mostly used for pests like Silverwing Familiar and Inquisitor Makto

Shadowlands Tyrant - Explained earlier, the card is just great.

Lethrai Provocateur - Probably a flex slot, this is a card that is great against Armory and Foregemasters and if you are really lacking for a turn four play. But it's by far the least common market pull.

Powerbase :

The only other card that needs explanation is Amethyst Waystone. Basically, this helps us hit our 5th power on time, and because our deck is better optimized than the AI decks, having both players draw an extra card will be favorable for us over the long term. Against the AI nightfall deck, it can be a bit unfortunate, but that deck is able to keep nightfall going so consistently anyway that the drawback hardly matters.

I also don't run the warp power card because it reduces the chance of hitting Tasbu on five, but this decision may or may not be correct. My results are below:

Results:
Minions of Shadow
Argenport Shootout
Unseen Masters
The Strangers
Merciless Stonescar
Rebel Forces
Power of Progress (Loss)
(6 win)

Relentless Onslaught
War Scavengers
Arcane Might
Harsh Elements
Apex Predators
Shields of Order
Limitless Possibilities
(7 win)

Grenadin Revolt
Merciless Stonescar
Students of Time
Elemental Mastery
Harsh Elements
The Enlightened
Defender of the Spire (Loss)
(6 win)

Unseen Masters
Kosul Heroes (Loss - stuck on 2 for 6 turns, on the draw no less, with Rhysta in opening hand.)
(1 win)

Forgemasters
Blackhall Bullies
Unseen Masters
Heart of the Vault
Airborn Assault
The Enlightened
Highly Skilled
(7 win)

Blackhall Bullies
Elvish Raiders
Airborn Assault
Tales of Elysia
Winds of Destiny
Chilling Touch
Sudden Death (Loss)
(6 win)

Airborn Assault
Arcane Might
Kosul Heroes
Hiding in Darkness
The Great Armory
Rising Up
Limitless Possibilities
(7 win)

Chaotic Rage
Minions of Shadow
Skycrag Blitz
Army of Justice
Best Served Cold
The Enlightened
Company of Exiles
(7 win)

Kosul Heroes
Strength in Numbers
Arcane Might
Unseen Masters
Primal Fury
Midnight Storm
Highly Skilled
(7 win)