When I first saw Niv-Mizzet Reborn I was pretty hooked. While I knew it was no drafting cube card nor even that viable for any of the cube constructed formats I was suckered in by the cool design challenge it posed and spent many an hour theorizing about it. I wanted to maximize the trigger which outlined a fairly defined deck structure of even split two colour gold cards. It all felt very much like a novelty joke deck but that didn't stop it being intriguing. It isn't viable for draft as you cannot hope to get the right ratios while also making a sensible deck and mana base. It isn't great for constructed cube either as you want all the best lands and that is pretty hard to fight everyone else at the table for. Commander and apparently modern are the places best suited to Niv.
I had two main plans for my cube build, a control list and a midrange one. Both had the same mana base and ratios of cards. Both were 16 land and 24 spells of which there were exactly two of each Guild pairing so an average Niv trigger would draw around five cards. Both decks looked very similar with many of the same spells as well as structure. The control had less creatures and more mass removal and counter magic but that is all. I ended up doing the midrange list first as I wanted to play Hero of Precinct One!
While playing the games I very quickly realized I had wildly underestimated the power of Niv. Turns out you don't need to get anywhere near five cards drawn on average for the card to be absolutely nuts! Pretty obvious in hindsight... the old five mana 6/6 flyer with upside. You could slash the number of targets to 20% and the card would still be very strong. You don't need an even split five colour deck with over half you cards gold. You can build a three colour deck and splash in the Niv. You really can do whatever you want. As you move away from drawing roughly five cards on average you greatly increase the freedom on the deck and thus what kind of thing you can do. Drawing two or three cards on average is effectively as game winning as five cards when a lot of what you did was also make a huge dragon. Niv is nuts and I can totally appreciate how he is able to compete in modern. Now that I know he is not just a card for memes and how flexible you can be with him I will absolutely be doing more brewing with the card. Here is the midrange list I learned all this with. It didn't drop a game.
24 Spells
Mox Diamond
Safewright Quest
Deathrite Shaman
Birds of Paradise
Hero of Precinct One
Eladamri's Call
Lightning Helix
Fire / Ice
Arngarth's Rampage
Castigate
Lim-Dul's Vault
Growth Spiral
Coiling Oracle
Dovin's Veto
Pernicious Deed
Ionize
Kolagahn's Command
Vindicate
Domri, Anarch of Bolas
Teferi, Time Raveler
Huntsmaster of the Fells
Nahiri, the Harbinger
Hostage Taker
Niv-Mizzet Reborn
16 Lands
Lots of Sacs, Shocks and Duals!
When testing this I had a very greedy mana base with four sac lands and a near full complement of exactly the sacs and shocks I wanted. I figured the deck would just be too clunky and slow without but in hindsight it would have worked absolutely fine just packing some Vivid lands and cobbling together whatever else you can. Essentially you could well do this deck in a rotisserie setting, only fight a little on lands and still have a really good deck. You could do this for an even split five colour deck or you could have an even easier time of the draft, get more of the premium lands you want and increase your overall consistency by aiming at a three colour list with a double splash. My underrating of Niv and over estimating how much you needed to support him made me over compensate in all areas including mana base. The assumption that was needed led me to believe the deck would be inflexible and infrequently viable all of which is untrue.
The game play is very simple. You cast your high powered gold cards and just survive and ramp through the early game. This is pretty easy as your spells are so good. Then you cast one of your game winning bombs and it continues to be easy mode. The only thing I found even slightly difficult about playing this list was using sac lands. I repeatedly hit seven cards with Niv averaging over six as a result, somewhere between turn four and five as well. It felt impossible to lose at that point. Your opponent knows it as well when you go to discard and drop things like Helix they have targets for or just top end power you can cast. Very demoralizing for your opponent!
Of the brews I do in cube format this is easily one of the best to translate into commander. Always having your Niv is amazing. There is no real shortage on power in the gold card area either. You can just scale the whole thing up by 250% and run 40 lands, 5 gold cards from each guild and have ten spare slots left over too. The only awkward thing is that you want a lot of ramp in commander and there is less of that in the gold department. You likely have to play a set of Borderposts and use up a number of your free slots to arrive at a sensible looking list. The main issue for this as a commander deck is that you do rather more want the full set of ten of each dual, shock and sac land within your mana base which is several thousand pounds worth of lands.
There is not much more to say on the playing of this list. It is just bomb cards that are pretty self explanatory. The interesting part was in the theory and building. It is a fun shuffle swapping around cards. Normally you can have your ratios correct and then just swap like for like so as to get the best curve or synergies. In this build the shuffle often goes off on a chain event as you need to upset the balance in other guilds. Swap a Voidslime for a Dovin's Veto and now we need to find a Simic replacement for the Azorius card we took out. This is hard to do directly and involves large reshuffles to accommodate what initially felt like a small change.
In designing this list I scoured the guilds for all the cards I might want to run in such a thing. They are listed below within their colour pairs. Sadly I am not very familiar with the more powerful top end cards in commander and only listed the cards that are good in heads up play. As such I wouldn't use this as an exclusive list to build a decent multiplayer list with. It is certainly a good place top start you off with and should cover a lot of your low end. That being said, EDHREC is clearly the go to resource for things you should be looking at for your Niv commander deck and was certainly a big help for me in my design process.
Golgari
Deathrite Shaman
Pernicious Deed
Find // Finality
Maelstrom Pulse
Assasin's Trophy
Putrify
Abrupt Decay
Vraska, Golgari Queen
Golgari Charm
Vraska, Relic Seeker
Casualties of War
Meren of Clan Nel Toth
Simic
Growth Spiral
Voidslime
Coiling Oracle
Nissa, Steward of Elements
Hydriod Krasis
Incubation // Incongruity
Reason // Believe
Bring to Light
Mystic Snake
Rakdos
Angrarth's Rampage
Dreadbore
Terminate
Blightning
Bedevil
Kolaghan's Command
Daretti, Ingenious Iconoclast
Olivia Voldaren
Azorius
Absorb
Render Silent
Dovin's Veto
Supreme Verdict
Teferi, Hero of Dominaria
Teferi, Time Raveler
Time Wipe
Ojutai's Command
Azorius Charm
Depose // Deploy
Grand Arbiter Augustin IV
Selesnya
Safewright Quest
Eladamri's Call
Knight of Autumn
Qasali Pridemage
Kitchen Finks
Voice of Resurgence
Selesnya Charm
Dromoka's Command
Dimir
Baleful Strix
The Scarab God
Hostage Taker
Countersquall
Undermine
Lim-Dul's Vault
Thought Erasure
Thief of Sanity
Ashiok, Nightmare Weaver
Discovery // Dispersal
Silumgar's Command
Dimir Charm
Orzhov
Castigate
Gerrard's Verdict
Tidehollow Sculler
Sin Collector
Vindicate
Utter End
Despark
Consecrate // Consume
Anguished Unmaking
Kaya's Wrath
Kaya, Ghost Assassin
Kaya, Orzhov Usurper
Oath of Kaya
Merciless Eviction
Sorin, Grim Nemeis
Kaya's Guile
Izzet
Ral's Outburst
Ral, Storm's Conduit
Dack Fayden
Electrolyse
Counterflux
Ionize
Fire / Ice
Izzet Charm
Keranos, God of the Storm
Lightning Helix
Warleader's Helix
Warleader's Helix
Nahiri, the Harbinger
Heartfelt Redemption
Solar Blaze
Deafening Clarion
Wear / Tear
Ajani Vengent
Assemble the Legion
Wear / Tear
Ajani Vengent
Assemble the Legion
Gruul
Domri, Anarch of Bolas
Fossil Find
Manamorphose
Reap the Past
Wrenn and Six
Wild Cantor
Firesprout
Branching Vines
Hull Breach
Cindervines
Bloodbraid Elf
Huntsmaster of the Fells
Assualt // Battery
Struggle // Survive
Unguilded
Tome of the Guildpact
Firemind Vessel
Farseek
Mox Tantalite
Hero of Precinct One
Noble Hierarch
Brainstorm
Preordain
Pillar of the Paranus
Urza's Filter