This primer is also posted to my friend's blog. You can find it here.

Grenzo, Dungeon Warden is a pretty strange card. He's one of only three legendary creatures with an X in the mana cost. He is one of only two cards (that I know of) which interact with the bottom of the library beyond just putting things there. Also, his hands are bigger than his face, and he's just funky lookin in general.

So Wait, What Does Grenzo Do Again?

Grenzo lets you pay two mana (at instant speed, and repeatedly) to put the bottom card of your library into play if it is a creature of lesser or equal power to Grenzo. Since he is an X spell, his power is equal to the mana you choose to pay, letting the selection of creatures you can grab scale with your investment.

This suggests two strategies: either make Grenzo really big, and push out huge monsters on the cheap, or ensure that the creatures in your deck are small enough that even a mini Grenzo can get them. While the former is something I've tried in the past, I'll be discussing the latter here.

How Can We Win With Just Small Creatures?

Pretty easily, as it turns out. In RB we have access to some pretty nasty creature-based combos, the simplest being Kiki-Jiki, Mirror Breaker + Zealous Conscripts. Oh wait, did I not mention? This is a combo deck. Yes, I'm one of those guys you heard about in the Kangee deck tech. If you didn't want to read about that, you can stop here and go try to play Grenzo with Vampire Nighthawk or Herald of Leshrac or whatever.

I'll wait.

...

Are they gone? Cool. I lied about waiting.

The other standalone combo we're playing is Necrotic Ooze. Since we spend most of the game milling ourselves, and our curve is pretty low to begin with, the Phyrexian Devourer/Triskelion win isn't very reliable. I've opted for Kiki-Jiki + Mogg Fanatic in its place. Tap Necrotic Ooze to copy itself with haste, rinse and repeat until you have half a billion Oozes, then sacrifice them all to ping people to death.

I specify "standalone combo" here because there are numerous loops that require Grenzo to be in play, many of which have interchangable or surprising pieces. I will go over these in more detail later, but for now it's sufficient to get the idea of what the deck is trying to do: flip through as much of the library as possible, stabilize a loop, repeat until you've won.

Just Show Me the List Already.

Fine, fine. You can find the most updated list on Tappedout here.

Creatures

When I activate Grenzo, I want a greater than 50% chance of it paying off. As such, I run over 50 creatures.

Mana dorks are incredibly important to the deck's strategy. Ramping by only one land per turn is not sufficient, so there needs to be some amount of creatures that give you consistent mana increases across turns. This is both so you can flip increasingly large numbers of cards (which get you more mana), and so you can cast actual spells while still holding up Grenzo activations.

These creatures provide less reliable mana production, but generally in greater bursts. They allow you to flip more creatures in a turn than normal, leading to unexpected wins.

Recurring resources is pretty important here, as bringing back a key combo piece from the grave is generally easier than trying to get a funcitonal copy from the library. Epitaph Golem is the sleeper hit here, in its repeatability and the sheer number of combos it enables.

Sources of haste allow you to often play one turn ahead with mana dorks and reanimator creatures.

If there's one thing Rakdos is good at, it's removal. This package is relatively small compared to what we could be playing; in a meta with more things like Linvala or Elesh Norn, I would definitely expand this list.

Some combination of these creatures is responsible for the vast majority of the deck's wins. Again, I'll give a more full list of combos later on.

These guys are more generalized utility. The slots are pretty flexible, none are required for the deck to accomplish its plan.

So there's all your creatures. The non-creatures have to be pretty darn good to justify the slot, so I'll address these individually.

Instants

The most flexible removal in Rakdos. The only mana-efficient way to permanently deal with enchantments. Required.

The spot removal I play needs to be either super flexible or so cheap you don't need to pay for it.  Fire Covenant and Snuff Out currently fill those roles.

Pyroblast and Red Blast are really nice "gotchas" to have in your pocket. You could play both; I like just the one to keep the fear in 'em.

None of the modes individually are good enough, but the flexibility lets this make the cut. It has game against nearly any opposing combo, can shut off value engines, and blows up that nasty early game Sol Ring. Couldn't ask for more.

Sorceries

This one is something I'm trying out. The flashback on this is the only reason it's here, since it's more likely to hit the grave than it is to be drawn.

This should probably go in every red deck, honestly.

Artifacts

Convert a creature into another flip. Seems fair, given that it's roughly a 50% exchange rate with the deck's composition, and it is fair, until you combine it with other cards.

Just double your flips. That's enough.  The fact that I'm running Bracers should tell you how good Heartstone is.

Fixes iffy draws, recovers you from certain doom, goes crazy with Skirge Familiar. This is banned in modern for a reason.

Auto-include in... everything?

Enchantments

Oh boy, this thing. It's worth rephrasing exactly what this card does. Whenever a creature comes into play, on anyone's field, you get one colorless mana per creature you ocntrol that shares a creature type with it. If it was your creature, you get one mana for itself. If you stack triggers such that more creatures come into play with this ability on the stack, you can start getting mana on the order of polynomials. This card is actually absurd. If you untap with it, you will almost always win. I've seen someone try to Reclamation Sage it down, only to win in response because I controlled a Shaman, and that gave me enough mana to kill everyone on the stack. Of all the cards in the deck, this is the single one that will win the game on its own.

...What's that? You say there's one more? Oh... that one.

Okay, so Doomsday. You cast it, stack the 5 cards you need to win, activate Grenzo once, and you win. The competitive EDH version of Grenzo does exactly this, because it is in fact the most efficient, deterministic way to win with Grenzo. It's also, uhhhh... super boring. For the sake of fun, I generally don't cast this card that often. It's just way too easy, and turns the game into "Do you have an answer, like, right now? k i win."

If you really want to know what Doomsday piles work best:

If that won't work for whatever reason, you have to think. Odds are you won't have to think very hard. The only time I had to try when casting Doomsday, an errant Newlamog exiled a piece of every combo I had available. I could still find a way to win.

Lands

I've found running about 32 lands to be good for this deck. It can't afford to run too many real mana rocks, and there isn't all that much card draw, so going below that is pretty risky. Too many, and you dilute your Grenzo activations too much.

For the most part, this is the standard semi-budget Red/Black manabase. Notable inclusions are Cabal Coffers, which is pretty much only good if you accidentally the long game, and Temple of Malice, Spinerock Knoll, and Howltooth Hollow. These get their value from being able to stack the bottom of the library to some extent, allowing you to plan your flips in advance.

Notable Exclusions

The most obvious missing cards are tutors. Vampiric Tutor, Demonic Tutor, Gamble, Diabolic Intent, and more could all find their way into this list. As far as I'm concerned, they take a lot of the fun out of this deck, though. I'd never begrudge anyone for running them, but in a deck where the optimal play is almost always to tutor for Doomsday, then cast Doomsday, then win... No thanks.

Many cards are excluded for budget reasons. Badlands, fetchlands, Imperial Recruiter, and Mana Crypt are probably the biggest of these. None of them are really necessary, but all would be nice to have.

With an average CMC of 2.94, Ad Nauseum is not at its best here, and even if it were included, drawing tons of cards actually helps surprisingly little. Mana is nearly always the biggest constraint under which the deck works, not cards.

Budget

You can pick up this list for under $200. With a simpler manabase, it can still function reasonably well and drops to well below $150. Start dropping Bloodghast, Simian Spirit Guide, and a few others, and you can go even lower without significantly affecting the functionality of the deck. What I'm saying is, as far as commander decks go, this one is pretty darn cheap if you want it to be.

Okay, I Didn't Read Any of That. How Do I Play?

Generally speaking, I'll follow these guidelines when I play this deck.

  • Always cast Grenzo for X=1, or three power. This lets you get everything in the deck except for Necrotic Ooze, which will probably end up getting reanimated anyway. Only cast Grenzo for X=2 if it doesn't prevent you from activating an additional time, and even then probably not.
  • Never activate Grenzo at sorcery speed unless you're trying to win right now, or there's a problem you can't let someone untap with. You have instant speed interaction. Make sure your opponents know it. Even if you can't bluff, it's always possible to flip into something that opponents assess as a threat; it's better to do this when they can't answer at sorcery speed.
  • Don't always cast Grenzo as soon as possible. If you have stuff to do in your hand, it's sometimes worth running out mana and utility creatures when they don't have to compete with Grenzo activations. The longer Grenzo stays on the field, the more likely he is to die, and that can be a major tempo hit if you don't have recovery options.

Where's That List of Combos You Promised?

Sure, fine. This is a partial list. I'm constantly finding new combos and interactions.

Kiki-Jiki + Conscripts = Infinite hasty attackers

Necrotic Ooze + Kiki-Jiki and Mogg Fanatic in the graveyard = Infinite damage

(The remaining combos require Grenzo on the field, usually at X=1)

Mana Echoes + some quantity of starting mana = You probably win somehow

Doomsday + 2 mana + Grenzo = You win however you want

Ashnod's Altar + Heartstone/Illusionist's Bracers/Ogre Slumlord/Pawn of Ulamog = Every creature results in two more flips. Since we play over 50% creatures, on average this flips the deck, especially considering the creatures that add mana on their own.

Epitaph Golem + Workhorse = Infinite ETB and death triggers.

Epitaph + Workhorse + Zulaport Cutthroat/Blood Artist = Infinite drain

Epitaph + Workhorse + Ashnod's Altar/Heartstone/Illusionist's Bracers/Pawn of Ulamog = Infinite mana, flip your deck.

There are many more specific loops that can use Carrion Feeder or Viscera Seer in place of Ashnod's Altar, but these are generally too complicated to try to enumerate.  A representative example might be something like:

Epitaph + Priest of Gix + Viscera Seer + Heartstone = Infinite mana, scry, every creature in your library.

This Guy is Confusing. I Want to Play Something Else.

Well, if you want something from Rakdos specifically, you might have a bad time. Playable legends are relatively slim in this color pairing, with the best options likely being Kaervek the Merciless and Rakdos, Lord of Riots. Yes, I know Vial Smasher is a card. I also know that it's never just red/black, also shut up. Anyway, these clearly lend themselves to quite different strategies than Grenzo.

If you don't like Rakdos, and I wouldn't blame you, you can find similar abilities in Yisan, Alesha, Thrasios, and Mayael the Anima. All of these have their individual limitations relative to the Dungeon Warden, and their strengths.

This Has Gone On Way Too Long, Wrap it Up.

Grenzo, Dungeon Warden is a pretty cool guy. I've been playing him since I pulled the card in a Conspiracy draft over two years ago, and there's always something new to find. Practically every set gives him new toys to play with, even for a relatively focused combo list like this one. The fact that I wrote just... way too much about this should make it clear how much I like this deck. It's really cool.

Thanks for reading, folks. If you enjoyed this, consider checking out my youtube channel 1600 Horsepower