Card draw, tutors and damage - Grixis is a very formidable color combination. Grixis decks have had a major impact on the format for a long time - Nicol Bolas (Plus Fire Whip!) was one of the very first EDH decks - back when your "general" had to be cone of the Elder Dragons - hence the ED in EDH. One of the most powerful and popular Shards/Wedges, Grixis has a ton of com-bos, a ton of redundancy and a lot of sheer, unbridled power. I am going to do my best to group the combos I see in Grixis into different classifications and hopefully get you excited about building a Grixis deck.
Before I launch headlong into combosplanation, however, I want to talk briefly about where I did my research. Commander Spellbook is a community-driven archive of Magic card combos. What started as a project on Discord now has its own website. I used Commander Spellbook to look at the hundreds of Grixis combos in their database to see if I could group any into classes. It seemed daunting at first, but the website is easy to use and has lots of filters so you can or-der the combos based on how many cards they take to work, how many steps - you can even sort by price to find budget-friendly combos.
With that out of the way, what does Grixis love to use to combo off?
Thoracle
Grixis is one of the most popular homes for Thassa's Oracle decks. It has access to both Thassa's Oracle and Demonic Consultation, but other decks do as well. What sets Grixis apart from the rest is Kess, Dissident Mage and Maestros Ascendancy. These cards allow you to Consultation for Oracle then Consultation again right away. This power, consistency and small number of cards that aren't your commander makes Grixis an ideal home for Thoracle decks.
Infinite Turns
Time Sieve was a more common combo piece when Commander was a bit slower and more expensive cards were playable. It wasn't quick or easy, but Thopter Assembly was enough to take infinite turns with Sieve. We have gotten a lot of new, efficient combo pieces lately, and Grixis makes a lot of them shine. While Time Sieve is Blue and Black and can go off without Red in the deck, Red is a HUGE help. Dockside Extortionist and Olivia's At-tendants can routinely give you more than the five Artifacts you'll need to use Time Sieve again, for starters. Kiki-Jiki, Mirror Breaker can also make copies of creatures that give you tokens like Underworld Hermit or Abhorrent Overlord in addi-tion to those excellent Red token-creators. Some of these combos use a creature like Silas Renn, Seeker Adept or an equipment like The Reaver Cleaver, so you'll likely have to find a way to deal damage to a defenseless opponent, but if you do it once, you can do it until the game is over.
It's not just Sieve, however. Grixis has quite a few combos with other combo pieces, a lot of the time with the commander of the deck as one of the combo pieces. Players can do incredibly complicated combos with Anhelo, the Painter copying spells like Call to Mind by sacrific-ing the token from Talrand, Sky Summoner or Poppet Stitcher // Poppet Facto-ry. They can use Ichormoon Gauntlet and Jace, Cunning Castaway's copy ability to make a bunch of Nicol Bolas, Dragon God copies. Obeka, Brute Chronologist can end a turn where we're about to die to Final Fortune and let us do it again. Inalla, Archmage Ritualist can loop Timestream Navigator copies using any bounce or blink effect. Even Marchesa, the Black Rose has a combo or two, usually by looping a creature like Myr Battleshere to pay for Time Sieve. There are a ton of infinite turn combos and a lot of them either synergize with each other or at least can comfortably occupy the same deck without being dead draws.
Mairsil, the Pretender
Mairsil is largely forgotten, having been upstaged by Kess, Dissident Mage from day 1, which is a shame. Mairsril, the Pretender becomes a creature with a raft of abilities, some combination of which will end the game. There are 68 infinite combos with Mairsil listed in the data-base which means two things. One, I should rebuild my Mairsil deck and 2, I should submit one more Mairsil combo to the database. This combo page is basically a decklist - do yourself a favor and peruse all 68 combos, it's a genuinely fun time.
Mishra, Eminent One
Mishra, Eminent One seems a bit slow and clunky for a combo piece, but making a crea-ture with haste that has the abilities of one of your Artifacts actually opens up decks to a lot more combo pieces. Anything from Ashnod's Altar to Gonti's Aether Heart can form a powerful combo, usually with only two or three total cards that either wins the game on the spot or at least gives you an infinite number of all different kinds of triggers. Mishra making something that is both an Artifact and a Creature that is also a copy of something like Strionic Resona-tor means you'll need a way to convert a bunch of Strionic Resonator tokens en-tering play then getting thrown in a Krak-Clan Ironworks into damage, but it's a powerful engine and there are a ton of ways for this combo to pay off. Some combos on Mishra's page aren't immediately obvious - if you're confused about how a combo works, you can click on that entry to be taken directly to that combo's dedicated page and it will list any prerequisites and the order you need to take steps to pull the combo off.
Role Reversal
There aren't a TON of combos involving Role Reversal, but the Blue is necessary in a lot of these decks because without Blue, you only have Blim and Harmless Offering to give them Enchantments. Blue gives you access to a lot of cards like Legerdemain. The goal is usually to stick them with a card like Nefarious Lich to either vex them for a long time, or for a short time when you destroy it with Despotic Scepter. A few color combinations are OK at giving them permanents that will hurt them, and Grixis gives us access to Blue, which makes the deck quite a bit more consistent than if Blim were the commander.
Infect
You wouldn't necessarily expect Grixis to be an infect deck color combination, but we're not playing a typical infect build where all of our cards give someone one or two poison counters. Grixis infect com-bos win the game on the spot, either by giving Nekusar infect and wheeling or giving Lord of Tresserhorn infect and hitting them with a ten finger death punch.
Splinter Twin
Kiki-Jiki, Mirror Breaker does a lot of work in Grixis decks. There are a ton of different ways to make copies of important combo pieces in Red, and Blue and Black have some excellent ways to use that ability to end the game, or take infinite turns. Possessed Skaab and Vampire Charmseeker are no substitute for Snapcaster Mage in a typical game of Magic, but if we need to keep looping the same spell without exiling it, they join Archaeomancer and other creatures we can make a token copy of to keep play-ing Time Warp. You can even make Kiki-Jiki Blue somehow and make infinite copies of Norritt, which isn't good, but which does make me feel good because I recognized the combo potential of Norritt back in 1997. All it needed was cards that did... you know, ef-fects.
Infinite Damage
While Grixis benefits greatly from Red in ways that aren't Red's ability to turn iterations of a combo into ways to end the game, Red's knack for dealing infinite damage is no less important in Grixis com-bos. While Goblin Bombardment is a very common way to get something for all of your looping, Red also has a tendency to deal damage when something enters the battlefield. A lot of com-bos that would otherwise just make a bunch of tapped token copies of a creature suddenly have a way to turn that into damage - Some combination of Reckless Embermage, Impact Tremors and Mayhem Devil (plus many, many others) can make damage from just about any loop. Murderous Redcap is frequently featured in Grixis combos because with cards like Spark Double and Marchesa, the Black Rose you can allow Redcap to be the sole combo piece, functioning as both the looped card and the damage outlet.
Exacties!
To finish on a very fun note, Grixis, more than any other combination of colors, has a ton of combos that aren't easy to group together by anything other than the fact that they're not infinite. Rather than doing a loop a quadrillion times, you can simply cast Peer into the Abyss as a Nekusar player. You can give a 10/10 creature infect. You can use Mairsil, the Pretender to make their life total 4 with Tree of Perdition's ability then blast them with Spikeshot El-der's ability. There are plenty of non-infinite Grixis combos that win because they do exactly enough to win, and that's my favorite way to win. There is something so satisfying about winning with exacties - I consider it more style points to get someone for their exact life total or cards left in the deck than to deal them a billion damage. Niv-Mizzet the Firemind can kill an opponent very, very easily. Do you have enough cards in your deck, though, to kill 3 other people? Usually you don't, and that means you need to wait for the right time to use your combo, which is more fun to me, personally. Whether you're like me in that respect or whether you prefer to wrap things up on turn three so you and your friends can get in lots of reps, Grixis has combos to make your deck way more nasty, way more consistent, and way, way more fun.
Thanks for reading, and, as always, a huge shout out to Commander Spellbook who made this article series possible.