MTGNexus

I guess my central question is this: Is Brainstorm that amazing a cantrip without a glut of shuffle effects to remove the two unwanted cards? Or is it still a must-run in Ux decks that value cantrips?

In particular I've just been sort of unimpressed with it in Chun-Li / Zethi, Arcane Blademaster if I don't happen to have shuffle effects, compared to similar cards like Otherworldly Gaze, which take advantage of the graveyard. I'm looking at cards like Faithful Mending, Occult Epiphany, Hithlain Knots, Fact or Fiction, etc. despite the added costs. I'm still on the fence though because it still triggers "draw a second or more card per turn" effects and can potentially keep storms going.

Thoughts?

My short answer is that the ability to run them in place of more lands makes it usually right. 1 CMC cantrips are probably underrated by most players. Getting a land right now is the main reason to play Preordain Ponder and Brainstorm in most blue decks.

That said, they really only belong in decks with 18+ blue sources.

I always cut Brainstorm first if I am not running the full 9 fetches though. Ponder is the best then Preordain then I will sometimes run Portent and Serum Visions if I really want velocity.

Of the various one mana cantrips, I would say Brainstorm is pretty high-variance in terms of deck construction. It's hard to go wrong with Ponder or Preordain, and I love Thought Scour and Consider for graveyard-based decks (which is most of them).

But Brainstorm? In a vacuum, I don't think it's very good - you get to dig a little deeper into your deck, but it doesn't provide any actual filtering by itself. It does, however, go up massively in value if you can turn it into 'draw 3, discard 2' - one mana Thirst for Discovery is pretty above the curve. That usually means shuffle effects, but Oracle of Mul Daya, surveil/scry, and other ways to clear the top of the deck also work. Brainstorm is also good if you specifically care about drawing cards for The Locust God and similar cards, or if you want to manipulate the top card of your deck for Yuriko, the Tiger's Shadow or Cryptic Coat.

I'm not currently running Brainstorm in any of my blue decks - it doesn't really synergize with my blue commanders any more than any other blue cantrip, and I'm not running many fetchlands or other shuffle effects as support. Overall, I think it is weak in a vacuum, but strong with the necessary support.

I think it's good if you have draw synergy, like for Niv-Mizzet, Parun, instant synergy like Nymris, Oona's Trickster, or top of library matters like Yennett, Cryptic Sovereign.

I've never been one to run cantrip cards like Ponder, Preordain, etc in decks that don't specifically have a reason. I never run them to "smooth out draws" or think of them as ways to "dig deeper into your library".
However Brainstorm is the exception. There are three reasons. When a deck has top of library matter. When cards puts into a zone from library, so want to shuffle back in from hand. Finally the draw two element if you get a shuffle effect, note that I'm a huge fan of fetchlands.

I went through decks that have blue I've posted on Nexus and categorized them.
Decks that only have Brainstorm but not other cantrips (10 of 22): Obeka, Splitter of Seconds, Will & Rowan Kenrith, The Fourteenth Doctor + Clara Oswald, The Sixth Doctor + Romana, Sisay, Weatherlight Captain, Kinnan, Bonder Prodigy, Yorion, Sky Nomad, Niambi, Esteemed Speaker, Morophon // Kaheera, the Orphanguard, Aminatou, the Fateshifter.

Decks that have Brainstorm plus other cantrips (5 of 22); Kalamax, the Stormsire, Myra the Magnificent, Krark, the Thumbless // Ghost of Ramirez DePietro, Siani, Eye of the Storm // Eligeth, Crossroads Augur, Jorn, God of Winter & Kaldring, the Rimestaff.

Finally decks that don't run Brainstorm or any cantrips (7 of 22): Obeka, Brute Chronologist, Glenn, the Voice of Calm, The Pride of Hull Clade, Niv-Mizzet Reborn, Orvar, the All-Form, Chulane, Teller of Tales, Alela, Artful Provocateur.

I run Brainstorm in 70% of my u/X decks. The thing is that if you asked me why they are in the deck I can give you very specific reasons, as I don't just automatically include it in all my blue decks. But as you can see it is a high percentage still, where as the general concept of cantrips is pretty low for me. I don't have a single instance of where I run a cantrip card without also having Brainstorm in the deck.

Man you should run more Ponder, might as well be demonic tutor for how often it gets me out of jams :D if my deck runs blue as a main color it's running preordain and ponder. (20 ish blue sources)

I don't remember losing a lot of games where I kept a turn one ponder. Might be my favorite turn one play. :D

Brainstorm ranges from actual garbage when you don't have shuffle effects on the regular, to a legal Ancestral Recall when you do. Ergo the only reason you wouldn't play it is when you don't have shuffles.

The one mana draw spells are broken by any draw doubling effect like Teferi's Ageless Insight. If you are running, those they are extremely good. Drawing 6cards for U is just... disgusting. In Niv-Mizzet, Parun not only does he cantrip the spell, but if you do have a draw doubler out you are drawing 4 cards off of your Ponder.

But to answer your question, no, for any Ux deck though, I'm not sure I would run Brainstorm by default. The one mana dig spells are good I guess if you can either 1. refund the mana investment 2. copy them 3. need them for your storm count 4. need early game filtering/fixing

In the case of Zethi, Arcane Blademaster I would actually lean towards instants that have a bit more "kick" to them. You want to be getting more value for your kicker investment IMO. And I would definetly go for looting effects wherever possible to put bigger instants into my graveyard early game. Things like Frantic Search