doctorhydrogen

Odds are any situation where you're gonna want to cast Starstorm you could cast Blasphemous Act for more damage for less mana. Or alternatively you could run Magmaquake and have it only deal damage to non-fliers since almost all your dudes are in the air.

With all those mountains Valakut the Molten Pinnacle would be some nice free damage without much downside.

Myriad Landscape would be useful ramp.

Caged Sun seems like it would work really well here.

You've got a lot of draw already. Giving three cards to your enemies for each one you get seems terrible. Don't get me wrong; it's a playable card in situations like Nekusar or mono-white, Boros, etc. But you've got so many options in blue helping your opponents out at a 3-to-1 ratio seems like a bad idea. If you want one more draw just run Recurring Insight, or if you want slow repeatable draw Honden of Seeing Winds is only two more, and it doesn't put you down three cards (then 6, then 9, then 12, etc.) But I f*cking HATE helping people I'm trying to kill, so I might be biased :)

You're running enough planeswalkers to at last consider the Chain Veil.

Everflowing Chalice is one of those cards that's good in theory, but at four mana to get two out of it I'd much rather just run Extraplanar Lens or Caged Sun or Gauntlet of Power and get a whole lot more value. A Chalice can get you an extra spell per turn. A doubler can get you five.

Given how many cantrips and low-cost stuff you're running Future Sight could get you 3-4 cards a turn or more.

Now that tuck isn't a thing Spin into Myth is really expensive to remove a creature. I'd run Rapid Hybridization or something like Reality Shift if you're dealing with an indestructible-rich meta.

That's a lotta blue mana symbols that would love Nykthos.

Strip Mine is like four bucks and it's much better than Ghost Quarter.

Unless you're in a discard-heavy meta I'd run Expedition Map over Library of Leng. Map can fetch your Reliquary Tower if need be, effectively taking care of the no-max-handsize potion of Library, and it also ramps at the same time by getting you an extra tappable land. And if you have Tower (or Spellbook) already it's still ramp, where as if you've got one of those two already Library isn't giving you much.

Tolaria West would be useful. It'll fetch Reliquary Tower (my use 90% of the time) or Nykthos or Strip Mine to deal with an out-of-control Cabal Coffers or Gaea's Cradle or Serra's Sanctum or Valakut.

For one more mana than Turn to Frog, Polymorphist's Jest turns all an opponent's creatures to frogs for the turn, not just one. Plus since it's targeting the player not the dude it gets around hexproof/shroud.

Couple more cards that worked really well in my Brion deck:

Angelic Accord: Chuck a dude which gains you life, which makes an angel, which you can chuck next turn to get life which makes an angel, etc.

Martyr's Bond: Everytime you sacc a guy everyone else has to do it too.

Few things more boring than Simic goodstuff (or goodstuff in general), but that said:

I'd find a slot for Alchemist's Refuge. Being able to flash stuff in end of turn or in response not not needing the counterspell mana you kept open can be invaluable.

I like Dissolve as a counterspell, but I personally wouldn't run it over Dissipate. At least in my meta Scry 1 is never going to be worth as much as exiling that Avacyn or Elesh Norn so it can't be recurred, etc.

33 creatures is almost enough to make Lurking Predators a bomb.

Conjurer's Closet could do good work here. Prime Speaker, your clones, Coiling Oracle, Snapcaster, etc. all would benefit from it.

Serra Avatar and Malingus are pretty great dudes to throw.

Gift of Immortality lets you chuck the same dude over and over.

Thrumming Stone and Remembrance are all stupidly good in Athreos Apostles

That's kinda genius.

Doubling Cube maybe?

Beyond that:

Myridad Landscape is cheap land ramp that doesn't take up a card slot.

If you don't need a Reliquary Tower in your deck you're not drawing enough cards :)

Back to Basics will end some people. So can Quicksilver Fountain.

Future Sight is probably the best card draw engine in Talrand. I've countered my own spell with the top card just to reveal another card to cast which I then countered with the card below it. With enough mana you can chain half a dozen cards in a row off the top.

Speaking of mana, mana doublers are your friend. You've got Caged Sun, but Extraplanar Lens and Gauntlet of Power are great, as is Fabricate to find any of the three. Lens and Gauntlet aren't really budget, however, so I get not running them.

The more spells you cast a turn (and it should be a lot) the more mana Sapphire Medallion saves.

Switcheroo > Mind Control (or even Control Magic). It can't be remooved with a Disenchant effect AND it makes a drake for the same mana cost.

Mind Games is four mana to lock down the scariest creature and make a drake every single turn.

Mystic Speculation is three mana to Scry 3 and make a drake every single turn.

IMO lots more cantrip/draw spells (Brainstorm-type cantrips or Recurring Insight-type bombs) and a lot less counterspells or you're going to just run out of gas on like turn five while simultaneously painting a huge target on your head because you're the asshole playing the all-counterspell deck. I originally built Talrand simliar to this just to annoy a dick in my playground with an all-red deck who hated blue, but after he quit showing up I modified it, and the less counters I ran the better the deck got and the less aggro is generated.

Stupid thing keeps posting comments multiple times :/

One dude you could consider is Yuan Shao, the Indecisive. He'll make all your guys unblockable with Iroas out.

Well you have Dicate of Heliod entered twice so that will open up a slot.

Me personally, I think you're fine on creatures. 24 plus a commander plus creature-makers like Elspeth is more than enough. It's more than I run in most of my decks, and I never have a problem.

If you want to remove stuff and add stuff, maybe find away to get a bit of draw. Wheel of Fortune and Reforge the Soul are good ways to refill your hand.

Well you have Dicate of Heliod entered twice so that will open up a slot.

Me personally, I think you're fine on creatures. 24 plus a commander plus creature-makers like Elspeth is more than enough. It's more than I run in most of my decks, and I never have a problem.

If you want to remove stuff and add stuff, maybe find away to get a bit of draw. Wheel of Fortune and Reforge the Soul are good ways to refill your hand.

Well you have Dicate of Heliod entered twice so that will open up a slot.

Me personally, I think you're fine on creatures. 24 plus a commander plus creature-makers like Elspeth is more than enough. It's more than I run in most of my decks, and I never have a problem.

If you want to remove stuff and add stuff, maybe find away to get a bit of draw. Wheel of Fortune and Reforge the Soul are good ways to refill your hand.

Get a Lurking Predators in that deck posthaste!

Chromatic Lantern feels like a must-include for color fixing.

Mana base is harder. City of Brass, Exotic Orchard, Reflecting Pool, Meteor Crater and Command Tower are nice five color bargain options. Shocklands are good and reasonably priced at the moment, and the Odyssey filters are around a buck fifty each and don't come into play tapped. You could also run all five Vivid lands.

Crackdown would do good work here.

IMO Myriad Landscape is worth running in any non-green mono deck.

Since budget doesn't seem to be an issue and you already have Land Tax I'd find a slot for Scroll Rack, too.

I'd also run either Return to Dust or Fate Forgotten over Disenchant. There's nothing worse than holding a Disenchant and being unable to do anything about that Purphoros or Darksteel Plate, etc.

Also for one more mana than Glory of Warfare you can run Dicate of Heliod and give all your dudes +2/+2 all the time, and you can flash it in as a surprise too.

33 lands is really, really lean in a three color deck. I'm running 36 in mine, with more land ramp, and a lower curve, and even that sometimes feels like I'm not running enough.

IMO Damnation is radically overrated in EDH. I've never ever had a Toxic Deluge or Black Sun's Zenith in hand and wished it was a Damnation but I can't cound how many times I've had a Damnation or Wrath of God and wished it was a Deluge or Zenith as I stared at an Avacyn, Tajic, Theros god or Marchesa about to do something nasty. Plus playing Mimeoplasm you really want that Avacyn in the graveyard so you can copy it :)

Lightmine Field is probably slightly stronger than Powerstone Minefield in Iroas. I myself run both, but given a choice I'd run Lightmine.

With 37 creatures, Lurking Predators could easily put 2-3 creatures into play per round. Seriously, in this deck it would be stupidly good.

All those green mana symbols are going to generate a ton of mana with Nykthos, Shrine to Nyx. I'm also a firm believer every deck should run a Reliquary Tower. If you're not drawing enough cards to need one then you're not drawing enough :) Wirewood Lodge is a good way to untap elves with a strong tap ability, too.

Even if you add Nykthos and Reliquary Tower and Wirewood Lodge, that's only four non-basics in the whole deck, which means its worth looking at Primal Order. It can flat out end people. I dropped it in turn nine in a four player game the other night, and the other three people each had no less than 8 non-basics out. It did 16 damage to two people and 8 to the third before someone removed it. And that's far from the most damage I've seen it do.

Hall of Gemstone can be equally effective. For starters it basically makes your spells uncounterable since blue mages can't make blue mana on your turn. Beyond that though it can completely hamstring three-color decks, and it hurts two-color decks pretty bad, too. They have to pick one color spell to cast, which means no multi-color spells, including their commander. It's brutal.

Steely Resolve would give a lot of your dudes shroud. Not sure I'd run it myself since you've got Asceticism but it's worth a ponder.

Unless you see a lot of mono-green decks Vernal Bloom is gonna help you a lot more than everyone else.