Explorer #1 Mythic 5C Widespread Thieving Niv Deck Guide

Hey everyone! Today I’m going to be covering my Five-Color Widespread Thieving + Niv-Mizzet Reborn deck in Explorer which I recently used to get #1 with on the Arena ladder and also went 31-9 with in the new Constructed Events.

This is a 5 colour control deck using Niv-Mizzet Reborn to refuel and close out the game and utilising Widespread Thieving to help solve a lot of the mana problems Niv decks have had in the past while also helping you to dig for Niv-Mizzet Reborn. This is one of the most fun decks I’ve played recently and I’ve also put up a video on my YouTube channel with a full constructed event’s worth of game play if you’re interested in seeing the deck in action.

Main Deck

Niv-Mizzet Reborn: This is the centerpiece of the deck and it works as a great way to refuel as well as providing a huge body that you can use to both stabilise and close the game out.

You’re generally happy if you hit two or more cards off its ability so you don’t need to go overboard on trying to fit cards of every colour pair into the deck – it’s much more important that you run high quality two colour cards so that your deck operates well when you don’t have Niv-Mizzet Reborn, rather than forcing yourself to run cards in other colour pairs when they’re not as impactful. This is why I’m happy missing certain colour pairs out as well as being able to run a few cards that Niv-Mizzet Reborn can’t hit like Widespread Thieving and Omnath, Locus of Creation.

Widespread Thieving: There are two main problems I regularly encountered with Niv-Mizzet Reborn decks in the past and Widespread Thieving goes a really long way to help solve both of them.

Firstly, since you’re running a 5 colour deck, the mana base can be a bit shaky every now and then. Overall, there are definitely enough good dual lands in the format to make it work consistently, but you’ll still occasionally run into problems and the faster decks can really punish you for stumbling on mana when you do.

The second and slightly bigger issue is that mana is a real choke point, and what I mean by that is you’ll often have a lot of spells in hand, but not enough mana to cast them, especially after you’ve refuelled with a Niv-Mizzet Reborn. Most of the time you lose with a Niv-Mizzet Reborn deck, you’ll usually get out tempo’d and lose.

Widespread Thieving really helps to solve both of these issues as it produces a treasure token whenever you cast a multicoloured spell. In essence, this basically reduces the cost of all of your multicoloured spells by 1 mana, but it’s actually even better than that, as if you don’t use the treasure that turn, it actually nets you additional mana for following turns, and it also fixes your mana since treasures can produce mana of any colour!

Widespread Thieving works incredibly well leading into your Niv-Mizzet Reborn turn too, as you can play Widespread Thieving on turn 3, and if you cast a multicoloured spell on turn 4 and you don’t spend the treasure, you can then cast Niv-Mizzet Reborn on turn 5 and you’ll have two treasures available which means you can hold up instant-speed interaction the same turn to defend your position (as most of your interaction is 2 mana and instant-speed) which is very reminiscent of Teferi, Hero of Dominaria.

Additionally, if you can get two Widespread Thieving onto the battlefield, all of your 2 mana multicoloured spells are essentially free at that point, so the treasure generation is so strong at helping produce huge amounts of mana, and the games where I resolve a Widespread Thieving make the deck feel significantly stronger.

On top of that, you also get the hideaway ability which means Widespread Thieving will always replace itself with the best card from the top 5 cards of your library. This is really strong as it allows you to dig for your more powerful cards like Niv-Mizzet Reborn, Omnath, Locus of Creation, and The Scarab God, but even hitting Expressive Iteration or removal is fine and ensures you’ll always have an extra card to play off the excess mana that Widespread Thieving provides.

The Interaction

Tyrant's Scorn: I wanted to have a 4-of in this slot dedicated to dealing with creatures in the early-game and I also wanted it to be instant-speed as a consideration for the Greasefang, Okiba Boss decks. There are three cards that meet the criteria here: Vanishing Verse, Tyrant's Scorn, and Justice Strike.

Even though Vanishing Verse is probably the most generically powerful of the three, I discounted it almost immediately as it can’t kill Greasefang, Okiba Boss which is a huge issue, and there are also a number of other multicoloured creatures like Mayhem Devil, Bloodtithe Harvester, Gruul Spellbreaker etc. that this can’t deal with either.

Between Justice Strike and Tyrant's Scorn, I definitely prefer Tyrant's Scorn overall as it kills the biggest variety of creatures – Justice Strike not being able to kill Bishop of Wings or Righteous Valkyrie against Selesnya Angels or Supreme Phantom against Mono U Spirits for example is a big issue, and even though Tyrant's Scorn can’t kill bigger creatures like Korvold, Fae-Cursed King, it at least has the option to bounce them.

Additionally, you can use Tyrant's Scorn to bounce your own creatures which is particularly nice as a way to re-use your Niv-Mizzet Reborn if you run out of gas.

Assassin's Trophy: I’m not usually a big fan of running this card since giving the opponent a land is a pretty big drawback, but I feel it’s really necessary in this deck, and the way the deck works goes a long way to mitigate the drawback too.

This deck has such a strong late game because you almost never run out of gas due to cards like Niv-Mizzet Reborn and Expressive Iteration, and your late game usually boils down to attacking with your big creatures while always having answers in hand for whatever the opponent might play.

We’re really strong against creatures because of the creature removal and the life gain we get off both Deafening Clarion and Omnath, Locus of Creation, but without Assassin's Trophy, we don’t have a good way to deal with non-creature threats which is a big issue.

If the opponent has removal to keep our creatures off the board, we don’t really have a good way to pressure or kill planeswalkers which is a big problem, so Assassin's Trophy being able to cleanly kill planeswalkers is huge. There are also a number of artifacts and enchantments that will run away with the game if they’re not dealt with like The Great Henge, Trail of Crumbs, Witch's Oven etc. so without Assassin's Trophy, you could be way ahead on card advantage, but still end up losing because the opponent is able to keep up or run away with the game off the back of a planeswalker/ artifact/ enchantment that you can’t kill.

The downside of giving the opponent a land is typically a big drawback, but since we have such a strong late game, I’ve found it to not be much of an issue unless you use it in the first few turns of the game. If you end up using it on turn 2/3 and ramping the opponent very early on, that can lead to situations where the opponent can get way ahead on tempo and kill you before you stabilise, but I’ve found if you cast it on turn 4 onward, the extra land really doesn’t matter much because your mid-late game is typically much stronger than the opponent’s and the extra mana doesn’t matter as much the longer the game goes on.

Deafening Clarion: Dealing 3 damage to all creatures for 3 mana is a pretty good rate, and this is great at mopping up smaller creatures against both aggro and midrange decks. Having the option to also give your creatures lifelink is huge: since all of your creatures are big, they all survive Deafening Clarion and can then cause a huge swing in life totals if you can connect once they have lifelink, which is great at fully stabilising against decks that have good reach in the late game.

I’m only running 3 copies in the main deck because I feel the main deck is already well positioned against creature decks so 4 in the main felt like overkill but I do have the last copy in the sideboard for the matchups where its good.

The Other Cards

Expressive Iteration: This is potentially the best card advantage spell in the whole format and it fits perfectly into this deck. It’s obviously multicoloured so plays well with both Niv-Mizzet Reborn and Widespread Thieving, it helps us dig for both of those cards as well as removal if we need it, and it’s also very important at finding lands if we’re missing any colours in our mana base.

I feel like running 4 Expressive Iteration is very important alongside Widespread Thieving, as if you’re not running enough ways to refuel, you can end up in situations where you have a load of mana from Widespread Thieving and nothing to spend it on, so 4 Expressive Iteration alongside Niv-Mizzet Reborn usually guarantees you’ll always have a stacked hand to use with the extra mana.

Growth Spiral: Since mana is a big choke point in this deck, having access to ramp to get ahead on mana is huge at ensuring we can fully utilise our hand in order to ensure we can stabilise. Similarly to Widespread Thieving, the games where I can Growth Spiral on turn 2 make the deck feel much more powerful and tend to run a lot smoother. Growth Spiral also allows us to trigger the second landfall ability on Omnath, Locus of Creation which is really big and is another way you can get really far ahead on mana.

Omnath, Locus of Creation: This is a card I initially wasn’t running, then tested as a 1-of and very quickly moved up to a 4-of. Even if I wasn’t running Growth Spiral as a way to potentially trigger the second and third landfall abilities on Omnath, Locus of Creation, I would still be running it as a 4-of.

The name of the game with this deck is all about stabilising to reach your late game where you tend to run away with the game and no single card is better at stabilising than Omnath, Locus of Creation. The 4/4 body is great at blocking (and having an additional big creature you can use to turn the corner and start closing the game out is great) and the fact you basically gain 4 life every turn is so big at putting games out of reach for the opponent.

Before I was running Omnath, Locus of Creation, I was losing quite a lot of games where I’d stabilise it a fairly low life total and the opponent was able to force through the last few points of damage with something like Cat/Oven, Graveyard Trespasser/ Chandra, Torch of Defiance, burn spells etc. and so the 4 life a turn off Omnath, Locus of Creation is huge at ensuring the opponent isn’t able to race you (which is the main way aggro and midrange decks will be trying to beat you).

The fact it always replaces itself is also huge, and being able to sometimes trigger the second landfall ability off Growth Spiral and produce a load of extra mana is just the icing on the cake. Omnath, Locus of Creation is also pretty reasonable against control too as just an additional big creature we can apply pressure with that also replaces itself.

The Scarab God: This is more of a recent addition to the deck, but it fills a very important role. When I wasn’t running The Scarab God, I would sometimes get close to decking out against other very grindy decks if they have a lot of creature removal since Jegantha, the Wellspring, Niv-Mizzet Reborn, and Omnath, Locus of Creation were the only ways I had to close out the game. If they have answers for all of your threats, you no longer have any win conditions left even if you’re way ahead on card advantage.

The Scarab God as just a 1-of basically guarantees that you’ll win these longer games as it will usually single-handedly win the game on its own and is very difficult to kill permanently unless they can exile it. It can be used to reanimate Niv-Mizzet Reborn and Omnath, Locus of Creation from your own graveyard as well as single-handedly building up an army from whatever is in the opponent’s graveyard too.

Jegantha, the Wellspring: This is probably the deck that utilises Jegantha, the Wellspring the best as we have multiple strong ways to use the activated ability. It can produce mana to cast both Niv-Mizzet Reborn and Omnath, Locus of Creation essentially for free as well as providing the mana to activate the hideaway cost on Widespread Thieving.

Outside of that, it’s another big creature we can use to stabilise and close out the game which a lot of decks can struggle to deal with, especially if they’re relying on red damage-based removal.

Mana Base

28 lands has felt like a good amount – you really need to be running a high number as you’ll tend to fall too far behind if you miss land drops and I could potentially see an argument to going even higher, especially since the deck is also running 4 Growth Spiral.

In terms of the lands themselves, we’re running a fairly even split of colours between triomes, shock lands, and check lands. I’m running slightly more red and blue sources since those are the most prominent colours in the deck but you can’t go too heavy in one direction because you need to be able to find all 5 colours consistently.

I’m also running a single basic so you don’t get blown out by Field of Ruin or opposing Assassin's Trophy (since they can essentially Stone Rain your lands for 2 mana if they see you’re not running any basics otherwise).

Sideboard

4 Dovin's Veto: This is here mainly for control and combo decks trying to cast expensive non-creature spells. The fact this can’t be countered is huge at ensuring we’re guaranteed to stop proactive plays like Teferi, Hero of Dominaria or Genesis Ultimatum which could potentially go over the top of what we’re doing in the late game.

It also works really well with the excess mana off Widespread Thieving as it can allow us to win counterspell wars to try and force through cards like Niv-Mizzet Reborn.

4 Siphon Insight: This is another card here for the control matchup. I wanted to have at least 8 cards in the sideboard for control as our main deck is pretty well set up against creature decks, but a bit softer to control and there’s quite a lot of weaker cards in that matchup that we want to cut like Tyrant's Scorn and Deafening Clarion (game 1 against control is definitely winnable though, as they’ll also have dead cards against us).

I initially tried some creatures in this slot, but since we don’t close out the game that fast, Farewell was a real issue so I wanted to ensure whatever I boarded in this slot didn’t get hit by Farewell.

I tested some planeswalkers like Teferi, Hero of Dominaria and Kaito Shizuki which are both great in the matchup, but control will tend to board in additional counterspells like Mystical Dispute against you (to counter Niv-Mizzet Reborn and Omnath, Locus of Creation) which also counter those planeswalkers so it’s very difficult to get them to resolve.

Siphon Insight on the other hand is a card that trades very favourably with counterspells since you’re usually going to play it during the opponent’s end step and it has flashback so you get a second activation. Basically everything in their deck after sideboard is a good hit off Siphon Insight (counterspells, planeswalkers and card draw are all great) so as long as you don’t hit just lands or creature removal, you’ll tend to bury them in card advantage and it’s very difficult for them to interact with it favorably.

2 Culling Ritual: This is here predominantly for the sacrifice matchup where I felt it was important to have some dedicated sideboard slots as they’re a deck where most of the power comes from their non-creature spells, which we don’t have as much interaction for in the main deck outside of Assassin's Trophy.

Since we have a lot of interaction to deal with their creatures, the main cards that pose a problem are Trail of Crumbs, Witch's Oven, and The Meathook Massacre, all of which are cleanly killed by Culling Ritual while also netting us mana.

3 Justice Strike: I wanted additional instant-speed interaction to bring in against Greasefang, Okiba Boss while also helping against other creature-based decks.

As a Niv-Mizzet Reborn deck, the main two ways you have of interacting with the Greasefang, Okiba Boss combo is either with graveyard hate or instant-speed interaction, and it felt like it made more sense to lean more into the instant-speed interaction since there aren’t that many other decks interacting with the graveyard (outside of Arclight Phoenix which is a lot slower in Explorer than Historic). Justice Strike is also nice at being able to deal with bigger creatures like Korvold, Fae-Cursed King too.

1 Deafening Clarion: Final copy of Deafening Clarion here for matchups where we want to try and maximise our chances of drawing it to either sweep the board or gain extra life.

Best-of-One (Bo1)

The only change I would make for best of 1 is swapping out The Scarab God for a copy of Justice Strike. The Scarab God is mainly in the deck for long grindy matchups which are typically less common in best of 1.

I also think that Greasefang, Okiba Boss decks are likely to be more popular in best of 1 so having extra instant-speed removal really helps in that matchup too. If you expect to face a lot of Greasefang, Okiba Boss, then I’d also consider swapping out a Deafening Clarion for a second Justice Strike, but that will make you weaker against go-wide aggro decks like Mono R and Gruul.

Matchups and Sideboard Guide

Rakdos Midrange

In	Out
+1 Deafening Clarion	-1 Growth Spiral

This is a good matchup overall as you have the much stronger late-game so they’ll be forced into the aggressive role. Stabilising isn’t too difficult since you have a bunch of creature removal, Deafening Clarion kills almost all of their creatures and it’s very difficult for them to outrace Omnath, Locus of Creation.

The only real concern here are their planeswalkers as they can be hard to kill if you don’t have Assassin's Trophy so always try and have a plan for if they cast something like Chandra, Torch of Defiance. Thoughtseize is also a card you need to be mindful of so it’s generally better to cast cards like Niv-Mizzet Reborn earlier if you can afford to so it doesn’t get hit by discard spells.

Mardu Greasefang

In	Out
+3 Justice Strike	-1 The Scarab God
+1 Deafening Clarion	-3 Growth Spiral

This matchup is all about ensuring they don’t combo off in the early game so try and hold up instant-speed removal wherever possible and you’ll pretty easily outgrind their backup plan as the game goes long. In order to dodge Thoughtseize, it’s usually a good idea to play Niv-Mizzet Reborn as soon as possible unless you need to hold up removal for Greasefang, Okiba Boss as the combo becomes a lot less threatening once you have a Niv-Mizzet Reborn in play.

If the opponent still has access to 3 mana after casting Greasefang, Okiba Boss, and they don’t have 4 power in play without Greasefang, Okiba Boss, then it’s usually better to wait until the Greasefang, Okiba Boss trigger goes on the stack at the start of combat to kill it, as that plays around them having a second Greasefang, Okiba Boss in hand and they won’t be able to crew the Parhelion II once it does enter the battlefield.

Izzet Phoenix

In	Out
+2 Justice Strike	-1 The Scarab God
+1 Deafening Clarion	-2 Growth Spiral

Since we’re not running any graveyard hate to shut off Arclight Phoenix, we’re relying on creature removal, life gain, and blocking with Niv-Mizzet Reborn in order to stabilise. Justice Strike is nice as additional removal to take out Crackling Drake and Arclight Phoenix, but it unfortunately can’t kill Ledger Shredder which is why I’m only bringing in 2 copies.

Arclight Phoenix is probably the most annoying threat in this matchup since we can’t shut off the graveyard, but they’re typically not as fast at setting that up as the Historic version which usually gives you enough time to stabilise using Niv-Mizzet Reborn or the life gain from Omnath, Locus of Creation or Deafening Clarion. Obviously a resolved Niv-Mizzet Reborn is very difficult for them to beat and will usually be good enough to win the game, but you need to be very mindful of Mystical Dispute as that can be a complete blowout.

I’ve found this matchup to be pretty reasonable but if you wanted to make this matchup better, you could consider swapping some Dovin's Veto for Mystical Dispute or swapping some Justice Strike for Unlicensed Hearse, but that will tend to make your control and other creature matchups worse as well as reducing the consistency of your Niv-Mizzet Reborn hits.

Jund Sacrifice

In	Out
+2 Culling Ritual	-1 Deafening Clarion
+3 Justice Strike	-4 Growth Spiral

This matchup is all about trying to keep them off their engine pieces whenever possible like Witch's Oven and Trail of Crumbs so your most important cards are Culling Ritual and Assassin's Trophy to that end.

Justice Strike is brought in to deal with Korvold, Fae-Cursed King which is another card you want to kill as fast as possible (try and hold up Justice Strike or Assassin's Trophy during their turn whenever you can to limit the amount of card advantage they get off Korvold, Fae-Cursed King), so if the opponent is playing a sacrifice variant without Korvold, Fae-Cursed King then I probably wouldn’t bring in Justice Strike.

They’re very good at chipping away at your life total with Cat/Oven, Oni-Cult Anvil and The Meathook Massacre so life gain off Omnath, Locus of Creation is crucial to stabilising (the lifelink from Deafening Clarion is also huge if you can connect, but I trim it since it’s much harder to connect in combat if they have cat/oven or Oni-Cult Anvil etc online).

Mono Blue Tempo

In	Out
+2 Culling Ritual	-1 The Scarab God
+2 Justice Strike	-4 Growth Spiral
+1 Deafening Clarion

This is definitely the worst matchup for this deck, but is still potentially winnable if your removal lines up well and you play carefully. Culling Ritual and Deafening Clarion are potentially game-winning if you can get them to resolve and I also bring in Justice Strike as additional cheap removal since you want to go lower to the ground in this matchup. Be aware that Justice Strike can’t kill Supreme Phantom and they can also fizzle it with Ascendant Spirit by turning it into a 2/3 in response (but will die again if it grows from the additional abilities).

Keeping their creatures off the board and then running them out of counterspells is the main way you’ll end up winning this matchup so try and bait their counterspells on your less powerful cards and save cards like Niv-Mizzet Reborn and Culling Ritual for last if you can so they’re more likely to resolve.

Playing more conservatively and keeping up instant speed interaction in the early game is very important as if they can set up Curious Obsession and protect it, it’s very hard to beat. Widespread Thieving is also really good in this matchup if you can resolve it: the excess mana it produces enables you to start casting multiple spells a turn and also paying for their counterspells since most of them are conditional.

Azorius Control

In	Out
+4 Dovin's Veto	-1 The Scarab God
+4 Siphon Insight	-3 Deafening Clarion
	-4 Tyrant's Scorn

This is a very grindy matchup post-sideboard, but Dovin's Veto and Siphon Insight give you an edge. Teferi, Hero of Dominaria is by far the scariest card from their deck since we struggle to deal with planeswalkers once they’re in play so always try and hold up Dovin's Veto or Assassin's Trophy going into their turn 5 if possible.

This is another matchup where Widespread Thieving really shines as getting ahead on mana will give you a huge advantage at either winning counterspell wars or being able to play through counterspells by casting mutliple cards per turn.

Expressive Iteration and Siphon Insight are the most important cards to get ahead in the early game and the overall goal outside of keeping Teferi, Hero of Dominaria off the board is to set up a window to resolve Niv-Mizzet Reborn, either when they’re tapped out or backed up by counterspells.

Embercleave Aggro (Mono Red/Gruul)

In	Out
+3 Justice Strike	-4 Growth Spiral
+1 Deafening Clarion

This matchup is all about stabilising and keeping them off Embercleave so you’ll generally want to kill all of their creatures as fast as possible. Deafening Clarion can single-handedly win you the game so you’ll usually want to keep any hand with that if you have the mana to cast it.

Omnath, Locus of Creation is huge at stabilising here unless they have Embercleave so getting that into play on turn 4 to start gaining life is usually a good plan (unless you have other removal you could use to keep them off Embercleave). Also be wary of Rampaging Ferocidon as that can shut off the life gain off Omnath, Locus of Creation and Deafening Clarion which can sometimes allow them to force through the last points of damage so considering holding onto your last piece of removal if the other threats in play aren’t that pressing.

Tips & Tricks

• If you’re planning on using The Scarab God ability during your turn, it’s usually better to do it during your upkeep in response to the upkeep trigger so you gain extra life and scry more cards – you need to set a stop during your upkeep to be able to do this.
• Even though you’ll usually want to use Growth Spiral to trigger the second landfall ability on Omnath, Locus of Creation during your turn, you can hold onto it and do it during the opponent’s turn instead to gain an extra 4 life if you need to.
• If you have two copies of Widespread Thieving in play, you’ll probably want to have ‘Auto Order Triggered Abilities’ unticked (under options -> gameplay). This is because you can end up in situations where you trigger both but you only have enough mana to pay the hideaway cost off the second Widespread Thieving activation which will mean you’re unable to cast the card under the Widespread Thieving which resolved first – if you order the triggers the wrong way around this can result in you being unable to cast the spell you want which could lose you the game in certain spots.
• Sequencing your lands is incredibly important in this deck to ensure you have the right colours available on the right turn, so think carefully about the order you play them in – this is important for both the cards in your hand as well as cards you could potentially draw.
• When you’re planning out the mana you have available, don’t forget that Jegantha, the Wellspring can tap for a mana of each colour and that you’ll still get an extra treasure off the hideaway card you cast off Widespread Thieving if its multicoloured.

Conclusion

This deck has been so much fun and feels really well positioned in the metagame right now, so if you can afford the wildcards, I’d definitely recommend it. Thanks a lot for reading!