We've seen a lot of very greedy manabases in this Standard format, including that of Four-Color Saheeli, but no one seems to be willing to add the fifth color, even though a lot of the fixing is well-suited to playing five colors.
At the same time, a lot of the lands are merely two-color lands. Cards like Attune with Aether, Evolving Wilds and Traverse the Ulvenwald that can find any color can get stretched too thin if they need to find too many colors. This is to say that there are real costs to playing five colors, and real reasons not to, but at the same time, we're close, and I think the bridging that gap hasn't been explored well enough.
After a good amount of testing, I can say that if you're willing to play Prophetic Prism, you can access your colors of mana in a five-color deck very consistently. I'll fully admit that Prophetic Prism is a fairly high cost, but it does offer some other benefits: it's an artifact on the battlefield and it's a profitable permanent to blink or copy with Felidar Guardian or Saheeli Rai.
The deck I've been working on most is a five-color version of Four-Color Saheeli. Here's where I'm at currently:
- 3 Walking Ballista
- 4 Felidar Guardian
- 4 Rogue Refiner
- 4 Servant of the Conduit
- 2 Tireless Tracker
- 3 Whirler Virtuoso
Prophetic Prism offers both but takes up space in the deck, so it essentially replaces some Oaths of Nissa and Chandra, as it's also my sticky blink target for my Felidar Guardians. From there, I'm essentially playing Walking Ballista over Chandra, Torch of Defiance as my other four-drop, but this doubles as a two-drop and also counts as an artifact for Unlicensed Disintegration. Maindeck Tireless Trackers further support my artifact count.
So the biggest question is, “Is Unlicensed Disintegration really worth it?” I'm not sure, to be honest. Harnessed Lighting is also great in this deck, and the deck already has more three-mana spells than it would really like. On top of that, Prophetic Prism is much worse than Oath of Nissa, especially in a deck that's using the Anticipate effect to find a combo. On the other hand, Unlicensed Disintegration may be the best card in Standard, and it makes the deck far better at attacking opposing planeswalkers in a format that seems to be shifting more and more toward being a battle of planeswalkers, and it's a much better and more reliable answer to large creatures like Torrential Gearhulk.
If it were just Unlicensed Disintegration, I'd say we were probably making the deck too clunky by adding an expensive cycler to facilitate an expensive removal spell, but that's not the whole story. The sideboard also contains four Fatal Pushes. I tried Fatal Push in the maindeck but felt like it was a liability in too many matchups, but it's outstanding against any Heart of Kiran deck, Mardu Vehicles specifically, and any G/B deck. The cheap, clean answer makes it hard for those decks to get under you, which they're counting on, and really makes black feel like it's pulling its weight.
As for the rest of the specific card choices…
Only three Whirler Virtuoso: This is likely wrong. It's defensible because Whirler Virtuoso is best as a sink for the other energy the deck is creating, so copies have diminishing returns; I really want to draw exactly one per game. On the other hand, the card is so good and the deck makes so much energy that I really want to draw one every game.
Three Walking Ballista: Walking Ballista with no synergies is questionable, but Mardu Ballista has shown that it's at least a viable power level for the format. This offers another early play in a deck that can be low on those as well as a late-game mana sink in a deck that can flood out. Getting the three damage out of Unlicensed Disintegration is extremely important, even if this is theoretically a combo deck, and the additional artifact is welcome to help that consistently happen.
I often find myself combining three damage from Unlicensed Disintegration with one counter from Walking Ballista to kill Gideon, Ally of Zendikar. Further, after sideboarding, it's an additional revolt enabler for Fatal Push. I've been satisfied with the card, but I'm not attached to exactly three. I could see playing two or four. It's not essential to what the deck does; it's just a functional card that rounds things out well. I thought about cutting one for the fourth Whirler Virtuoso before posting this list, but I really don't like what that does to the curve.
One of each Oath: Given that a large part of the role of these cards is that they're good to blink with Felidar Guardian and that they offer some benefit with Saheeli Rai, they clearly have diminishing returns, and deck space is tight. The mana has been very smooth as it is, and the artifact count has been working pretty well as is. Both have been working well enough that it's possible that I could get away with only two or three Prophetic Prisms and I could play additional copies of Oath of Nissa instead, which would help the overall power level of the deck, but that requires a lot of stress-testing on the mana.
Maindeck Release the Gremlins: This card is fantastic in the format, and it's kind of weird how rarely people maindeck it. It's fantastic against Mardu and Dynavolt Tower, as well as several fringe decks, but even in its bad matchups, it's been pretty good for me. It's solid against G/B, particularly since you're really looking for removal for Walking Ballista.
The only matchup where it's really a liability is against Four-Color Saheeli, and even then it can sometimes kill two Thopters. It also gains some value in this deck because of Prophetic Prism, as you can kill unnecessary Prophetic Prisms in the late-game in addition to whatever you're killing of theirs to get an extra Gremlin, and, in some cases to make sure the spell resolves. For example, if your opponent has a Walking Ballista, normally this would just be "2R: Destroy Walking Ballista," but with a Prophetic Prism on the battlefield it becomes "4R: Destroy Walking Ballista, make two Gremlins," because it resolves as much as possible as long as it has at least one target.
When I first started testing this deck, I was siding out the combo against everyone, which convinced me to just cut the combo entirely and a play a five-color value deck. That deck was pretty sweet, but without a way to close the game quickly, it was too weak against decks that my answers lined up badly against, like Aetherworks Marvel. I tried playing Negate maindeck on top of four Tireless Trackers to hedge against that kind of thing, but it just meant that it was too easy to draw the wrong half of my deck, so I learned my lesson and put the combo back in and just stopped sideboarding it out so often.
Here's a list of other cards I tried that I'm currently not using, since I'm not sure all of them are bad:
This was a big part of the reason I built the deck in the first place. I really wanted to blink Gonti, Lord of Luxury, but I think it's too much like Rogue Refiner: It just offers more of something you're already good at, and the mana is a lot better when you don't have anything that costs two of the same color.
I tried this in the sideboard, and even in the maindeck when I cut the combo. It's a good card, especially if you're playing a lot of counterspells, but with the combo, I think there are better ways to generate card advantage
When the deck had Negate, Disallow, Glimmer, Dispel, and four Tireless Tracker on top of the other value creatures, it played some really sweet games against control decks, but I think it's better for this deck to focus on its sorcery-speed proactive plays rather than trying to shift into an instant-speed deck.
Putting counters on Thopters is great, and this is fantastic with Saheeli. It's been in and out of Four-Color Saheeli decks in general, and it seems like people are settling on not playing it. It's a very expensive card to support a backup plan, so I think it's probably not needed or worth playing, but I could see one or two playing well.
This was the other sweet card I wanted to try when I first built the deck. Two mana to draw two cards, one of which is a creature you've chosen, is a very good deal, and this allows you to get back Felidar Guardian if you need it to combo or to rebuy Rogue Refiner when you're grinding. It's fantastic with Walking Ballista, since it's so much better in the late game, so the fact that this can give you extra access to it when you have six to eight mana is just a really strong effect. I ended up cutting it because Raise Dead is always going to have some bad matchups where your opponent isn't really trying to kill your creatures and I thought it was too low-impact as a sideboard card, but I think it's an overlooked card that's right at the fringe of Constructed playability.
My sideboard right now is very straightforward: Tireless Tracker to grind, Fatal Push to answer small creatures, Harnessed Lightning when I want even more removal, Authority of the Consuls against Saheeli, Negate against low creature decks like Temur Dynavolt Tower and Aetherworks Marvel, Dispel to protect my combo, and Release the Gremlins for Mardu and other artifact strategies.
Sideboarding in Common Matchups
Unlicensed Disintegration tends to trade down on mana with their threats. It's a good answer to Gideon, Ally of Zendikar, but Fatal Push is just better against them, especially when I have three Release the Gremlins to answer their Vehicles. If I suspect that they have Archangel Avacyn, I could see leaving some in instead of a Rogue Refiner or two.
I don't change much here, and I think that's fine. All my cards are good against them and Unlicensed Disintegration is fabulous, so I think I'm fairly well-positioned as-is. I'm not sure what the right mix of Saheeli Rai and Tireless Tracker is after sideboarding. It likely depends on how many copies of Authority of the Consuls they have.
It's possible I'm supposed to be cutting combo pieces here, since getting the combo to happen seems difficult, but neither piece really seems that bad, and I think the other cards I'm cutting are worse. Maybe Oath of Nissa should stay over a Felidar Guardian or something.