Gearhulk Toolbox: modern problems require modern solutions
Based on a deck that I used to play a lot during the Kaladesh era. The deck is built firmly around Refurbish and the fact that all of the gearhulks are artifacts. With heavy draw power and discard, the graveyard essentially becomes a pool of resources. Mill decks usually end up powering up the deck. This deck is also playable on MTG Arena in Historic format!
Through tons of test playing this is my current most successful iteration of this deck which includes plenty of field wipes, enchantment removals. Some cards to consider: Cleansing Nova
Sanctify - I often find myself unable to deal with pesky enchantments, adding just 2 of these seems to solve the problem.
Cathartic Reunion - drawing 3 cards is huuuge. Always discard anything that you cannot cast within 2 turns and always discard the gearhulks. The god opening hand is have at least 1 mountain and any basic land with 2 gearhulks and cathartic reunion.
Thrill of Possibility - this is essentially Tormenting Voice, always discard gearhulks or anything you cannot play within 2 turns, or extra lands. I also always play this at the end of my opponents turn in case they try to discard anything useful from my hand.
Tormenting Voice - draw card, just like the other 2 draw/discard cards. Always discard Gearhulks or anything you cannot play within 2 turns.
Kroxa, Titan of Death's Hunger - I kept running into this card and then realized that it fit well in this deck. It's used more a late game card. I'll toss it early with Tormenting Voice and Cathartic Reunion since early game discard isn't very effective. During the late game this becomes monstrously effective as my graveyard is usually pretty loaded to continuously return for strong field presense and constant discarding.
Meteor Golem - I replaced Embodiment of Agonies with this. Since I struggled a lot with non-creature permanents. This card is the perfect answer to Enchantments, Planeswalkers, Artifacts and synergies very very very well with Teleportation Circle to control the board AND get a free -1 card advantage over the opponent.
Refurbish - this is the bread and butter of the deck and is what makes the gearhulks to abusable. I always try to set up a discard of gearhulks in my 2nd turn from Tormenting Voice, Cathartic Reunion, thrill of possbility and refurbish them on turn 4. It sets the tone of the game at this point and flips any aggressive decks into the defensive.
Teleportation Circle - absolutely nutty in this deck. Usually once it gets established with a gearhulk it's not uncommon for opponents to surrender the match. It gives all of the gearhulks recurring triggers every turn. Also cleanses pesky enchantments like Pacifism.
Wrath of God - this deck frown upon hordes of creatures, so to counter that. We simply wipe the field. It's often funny when I see opponents play too aggressively in the first 3-4 turns only to get Thanos snapped out of existence then get locked into a gearhulk + teleportation circle lock. I also coincidentally wipe my own gearhulks along with them. But this deck intended to run only 1-2 gearhulks at all times. Play conservatively and your many means of revival refurnish, Bond of Revival should allow you to come up on top of a field wipe.
Cataclysmic Gearhulk - just another form a field wipe except it works on enchantments too. Generally I find it confuses people whom litter the field with enchantments and artifacts. Then on the following turn, I just play Noxious Gearhulk to remove the last creature.
Bond of Revival - A slightly more expensive revival spell but grants the creature haste. I find this works very well with all of the gearhulks and usually catches opponents off guard. Works supremely well with Westgate Regent since it immediately grow to an 8/8 with ward: discard card.
Combustible Gearhulk - The Main character of this deck. When this bad boy comes out, there is no right answer for opponents. It's a Win/Win for you and a Lose/Lose for the opponent. Milling 3 cards AND taking dmg is devastating for the opponent since it just means I have more things to revive and giving me 3 cards is also absurd. Again Teleportation Circle is ridiculously abuse-able with this gearhulk.
Ugin, the Spirit Dragon - I put this son of a bitch in here because I lost to a gear with this bad boy out. I soon learned that this also works really well in this deck. It functions mostly as a field wipe since most things I face have a lower CMC cost than my gearhulks. If Ugin doesn't have the blow himself up, not that it needs to be mentioned but it's basically GG.
Sideboard
My main issues is facing against creatureless, planeswalker heavy control decks. Despark, The Elderspell and Purphoros's Intervention are easy answers. But for the moment Kroxa, Titan of Death's Hunger is holding those slots.