UPDATE - 13-13 50% WINRATE

UPDATE:  So this deck is totally victimized by the Galvanic Iteration Epiphany Combo, and not actually all that great against the other decks.  We are 60% vs Izzet and MonoG and 67% vs Azorius and Gruul (Temur).   Unfortunately, we are 0-3 vs the Grixis Lier Decks, 0-2 against Sultai Ramp, and 0-1 against a few other random Aggro Packages.  I certainly dropped a few games through misplays, so this might be closer to a 60% deck in the right hands.  Also, since we built this, the Izzet decks havve split into either iteration strategies or dragon strategies, and we probably need some more Soul Shatter and maybe a bit less countermagic.  I am finding that the most overperforming card in the deck is Starnheim Unleashed.  If you can keep yourself in the game long enough, and can foretell this, the 4/4's with vigilance are cccchhhheeeaaappp! I wonder if this is really the biggest advantage of white in the deck (along with Vanishing Verse and Doomskar and it deserves another copy (or two).  The other thing I notice in this deck is that when you get up to Ephiphany, it's almost always a defensive move.  I board it out against Mono Green because they have too many trample threats.  The more I think about that, I wonder if it'd be worth playing a Jeskai version of this deck.  The removal package doesn't need black since there aren't too many large creatures running around.  I find that I'm getting the most out of Vanishing Verse When it can hit a levelled up Ranger Class, which isn't all that exciting if you can just play a control/treasure ramp shell and go way over the top with Starnheim Unleashed.  Siphon Insight Kind of feels like a worse Expressive Iteration.  It's card advantage, but only if you play the flashback side, and you're depending on your opponent's deck being good.  It does work when you pull their threats late.  Grabbing 1 of 3 Wrenn and Seven can lock up the board, but it seems like we might just want to play our own cards.  I'm guessing that Izzet is just a better deck than Esper or Jeskai can ever be.  Burn Down the House is such a versatile sweeper/finisher that I think the Galvanic Iteration decks are just going to take over.  While adding white might be nice, I'm not sure we actually need it to compete, and I don't think black is really doing everything we want it to.

I'm updating the list with the latest version I've been playing.  Hall of Storm Giants is the best finisher manland, Teferi is really only useful if you've stuck a celestus and have countermagic (which we don't run all that much of), and the mana base needed some double-sided taplands.

Okay so 5-2 isn't the most impressive sample size, but I have been tweaking a few versions of this and wanted to track the one that started actually working.  I played around with a few other cards and I think this list is correct.  Happy to answer any questions about deck changes I may have already tried in the comments!

Normally I writeup a deck with a plan to win, but this deck does not plan to win.  It just plans to make sure your opponent doesn't win.  Right now we clearly have two top decks in standard; Mono Green and Izzet Epiphany.  Those two decks have a very solid gameplan that takes advantage of some of the best two-for-one threats available in the format.  The goal of this ESPER deck is to prove that Wizards may have actually printed all the answers we need to challenge these two decks.  And with the printing of Siphon Insight, their wincons can become our wincons.

Just a disclaimer, this is a slow deck with almost no wincons.  We have the birds from Alrund's Epiphany, two copies of Cave of the Frost Dragon, and a single copy of Starnheim Unleashed.  Lucky for us, our opponents will be playing plenty wincons, so when you're ready feel free to snag something like Wrenn and Seven or Goldspan Dragon with one of the four (eight with flashback) castings of Siphon Insight.

The strategy for this deck is all in the sideboard, so game 1 can be tricky, and the list is set up to try to be a 'good against everything' mashup.  I'm going to just go through each card and list the advantages as well as sideboard strategy.

MAINDECK

We play two in the main and two in the sideboard.  This card is one of the main reasons we are playing black.  When you are up against Izzet (or even some of the Azorius lists out there), you can just start ripping counterspells out of your opponents hand.  Remember, that is what this is for.  You will have your own counterspells for their Alrund's Epiphany, and with Duress it's actually in our best interest to set up a 'counter-battle' in the beginning of control mirrors.  Remember, in control matchups we are almost exclusively interested in countering Epiphanies - we have access to great removal cards like Vanishing Verse, Infernal Grasp, and Fateful Absence for other threats.  I'll get to those later.

One of the reasons Mono Green and other green-based decks are winning is because their threats cover literally every different permanent type.  In addition to creatures, they have Ranger Class enchantments, Wrenn and Seven planeswalkers, and Esika's Chariot artifacts.  All of these leave a creature token or two on the board when they come down, so it's in our best interest to counter, or dump these cards out of our opponents hands in the aggro matchups before they hit the board.  We should have card advantage over these decks with Memory Deluge and Siphon Insight, so if you can snag one of their threats on turn 1 for a single black mana, we're way ahead.  Additionally, Green decks seem to try to sideboard around sweepers and spot removal with these threats, I'm finding I want to keep at least two in the deck post-board.  We might actually want to take the maindeck up to 3 at some point, but I am still only seeing Mono Green and Izzet about 40-50% of ladder matchups.  If you enter an event with this list, I'd swap a Teferi, Who Slows the Sunset for a Duress.

Unconditional Creature/Planeswalker removal.  Giving your opponent a card for 2 colorless isn't great, but we're relying on the fact that they can only draw so many threats in a game, and you'll at least be ahead on mana here.  The issue with a lot of creature removal is that the conditions just make them rot in your hand.  Conditionless with an added cost is the way to go.

Once again, conditionless creature removal.  Two life should be trivial with Meathook Massacre or The Celestus on board, but dont' run too many as drawing 4 of these in the game gets a bit too costly without dedicated lifegain synergy.

One in the maindeck, one in the sidebaord.  A bit wider than Test of Talents.  Against the green decks you need to focus your permission spells on Artifacts, Enchantments, and Planeswalkers instead of just Instants/Sorceries.

If you can set up your counter battles in control mirrors so you win with this card and exile all of your opponents Alrund's Epiphany you've pretty much won the game.

Who'd have thought this would be good?  In control mirror's you prioritize taking your opponent's counterspells - if you have 5 in your deck and they have 7, then you even the playing field by stealing one.  Once you stablize you can try to pull a threat out of their deck.  Pulling lands off the top doesn't hurt either.  Try to keep in mind that if you play this on turn two, and pull two lands off the top, they may struggle to find more - it may be worth it to burn a Test of Talents on an opponent's T4 Memory Deluge in this case.  We don't run Consider, so sometimes you will need to use this to steal lands in order to make your drops each turn.

This card is bomb in a meta where all the best threats are monocolored  Wrenn and Seven  Smoldering Egg // Ashmouth Dragon  Delver of Secrets // Insectile Aberration  Esika's Chariot.  It hits any permanent type, so feel free to eliminate those Ranger Class after your opponent has pumped 4 mana into the 3rd level.  Most importantly, though, you can exile those pesky Old Growth Troll's.

Not sure what to say here.  Standard conditionless 1BB counter with the upside of bieng a 1B if you can foretell.  Resilient against hand disruption as well if you find yourself playing the Grixis lists.  It feels like I have more information about how many counterspells are available for our opponents when they are foretold since they're often running 4x Alrunds and some number of these, you can generally assume that 1/2 - 2/3 of fortold spells are Saw It Coming.  We mess up that math with our Doomskar and Starnheim Unleashed, but some opponents will just think of the foretell zone the same way.  If you don't actually have the counters, you can just hold up however many combinations of 1B you need to win a counter war and pretend all your Doomskar and Alrund's Epiphany you have in the foretell exile zone are Saw It Coming.  Your opponent will have to respect it!

Ramp, Mana Fixing, Lifegain, Looting, and a great combo with Teferi allowing us to open up two mana after casting a spell.  Unfortunately this sometimes just gives our opponent a useful target for Prismari Command, but when it stays on board it can save you, and if they have to do that instead of loot or make a treasure, it's a win for us.

Meathook Massacre

If the aggro deck in the format wasn't green, then this card would be taking over standard in UB control.  It gets through 'indestructible' with -x/-x, and sticks on the board as an important lifegain source when you use spot removal.  This means your Infernal Grasp only costs 1 life, and you can send your birds from epiphany to their deaths kamikaze style since they'll still hit the op for 1.

2 of these are in the sideboard in case you see Scute Swarm or mono-white picking up popularity.  This is a serious blowout against the swarm, and mono-white creatures have a window where they are small enough for you to just get most of them with this, and gain back the life you'd lose from any that are out of reach.  Absolute gas against a deck full of X/1 and X/2's, and just makes all of your spot removal better.  If mono green wasn't so prevalent, and we weren't facing down a 6/6 hexproof troll so often on Turn 4, I think I'd swap a Doomskar in the maindeck.

1WW sweeper is totally necessary against Mono Green.  They just get too big too fast and can pump anything they have on-board.  Having these fortold gives you a nice safety net later in the game as well.  You'll often be using your spot removal on their 8 creature-lands, so you need to be using sweepers to 2 for 1 their standard creatures.  You still won't, since some of those creatures will be tokens from Chariot, Wrenn and Seven, or Ranger's Class (which they will continue to accrue value from), but eventually you should be able to take over with card advantage, sweepers, etc.

Honestly not quite sure about this guy.  If you have The Celestus on-board, then he's almost acting as the OG 5-drop Teferi, untapping two mana each turm without the extra card.  I have dropped him on board and just minused to select a card and let the op waste some removal.  4 mana to be up a card isn't that bad, and if you can stick him, then adding 2 mana in a control mirror is great.  You can essentially foretell a card for free every turn.  Also, if they waste a counter on Teferi, that's one less you need to worry about when the first Alrund's Epiphany is cast.  I board out all but 1 against aggro, and I'm not even sure that 1 is correct.

2 mana to foretell, then for W you can make as many 2 mana 4/4 flying vigilance angels as you want?  At the very least this will get the board to a state where you won't die.  Then if they overcommit, you can hit 'em with another sweeper and try to win with the final card here

SIDEBOARD

I don't have a guide written yet, still figuring out what works best, so I'll just go through how each one feels

Extra counterspell or blocker, then cast the disturbed side and your spells can't be countered.  Just be wary that they can hit the disturbed side with instant speed removal and then they are free to counter your counters.  Keep an eye on op's card count and do your math on each player's open mana.

4-of in control mirrors for sure.  Maybe not so much in the Grixis Lier deck since they don't run as many counters and might be able to get stuff out of the graveyard, but if you know you're playing that deck just save your Saw It Coming for Lier and save your Test of Talents for Epiphany and Galvanic Iteration.  Pretty simple deck for us to beat.

You just want 4 against Mono Green

I've found this to be helpful against the ramp strategies you find on the ladder.  Plopping two 4/4's can stop attacks from the mana dorks for a few turns,and that can be the difference between winning and losing.  Not sure if this is correct, but it feels good.  Plus you have one more white source to make sure Doomskar is online T3

Similar to Duress, worst case scenario is this gets countered.  Three mana is actually not a bad rate as you're often trying to hold this until they have only two (maybe 3) cards in-hand.  If it eats a counter, then great.  If it exiles a Memory Deluge from the graveyard, then that's also great.  Against aggro, if you can dump their two best spells (creature or otherwise) on T5 and hold up permission or removal for their topdeck you should be able to stablize and take over.

Tends to be better in the MonoG matchup than Test of Talents.  Add both to control matchups so you're playing mostly counters, sweepers, card advantage, and hand disruption.

Extra instant speed removal for Mono G.  Definitely the card to play against Koma, Cosmos Serpent strategies.  I might not play this at all in an event list, though.  There are too many Dragons, Angels, and Shapeshifters around for this guy to be as good as it shoud be.

You want two against control strategies.  You really want to draw one for Epiphany.  If you've got both, then hit their Memory Deluge or Behold the Multiverse with the other one.  Probably would go up one copy of this in an event list.

Meathook Massacre

Like I said, this is better than Doomskar if you're playing against Scute Swarm or a deck full of X/1's.  This card dunks so hard on go-wide strategies.  If you're playing black control and playing on ladder, this needs to be in your deck.

MANABASE

I'm not even going to pretend like I know what I'm doing with my manabase. I copy/pasted a grixis manabase from the Lier worlds deck and swapped some colors based on what I had crafted.  I actually love the slowlands.  You have nothing to do turn 1, so tapland doesn't matter.  Then play untapped T2, and we're off to the races after turn 3.  I only have 2 Brightclimb Pathways crafted (B/W double-sided land), but I don't think that offers us any real advantage over playing the U/B and U/W lands.  The 8x duals put us in a good position to have the mana we need.  Hold off on double-face decisions as long as possible.  We can't play the B/W snarls without adding a lot more basics.  Even with more basics, though, the snarls always come down tapped when you're topdecking.  Not worth it.  Might actually make sense to cut the Brightclimbs for an extra basc swamp and plains, or maybe a 3rd Field of Ruin.

I found that playing a lot of Jwari Disruption and Peleka Predation in other decks put me in positions where I couldn't play an untapped source when I needed to.  I think having untapped mana and playing on-curve is just too important in this meta to play a bunch of the modal double-faced cards.  The mythics that cost 3 life to come in untapped are too expensive in life and mana for the two matchups we're worried about, so I'm going to stick with a manabase that allows me to keep up with everything.  We're trying to play with a lot of open mana here, so taplands really set us back.

As far as creature lands go, I personally do not like the Hall of the Storm Giants.  I feel that the cost to activate negates the size and ward advantages, especially in our deck.  Basically I'm not activating unless the opponent has no cards in hand anyway, so as long as I can go over the top of other creaturelands I'm fine with taking a few more turns to do it.  Once we're there we should have the game locked up.  It may be better to use the Hive of the Eye Tyrant to get an even cheaper threat in there.  It's a little bit less evasive, though, and we need to have some extra white sources for Doomskar.

I have 3 basics in there for our two Field of Ruins, plus one of the Opponent's.  So hopefully you don't see more than 2-3 fields cracked per game.  Probably could use some tuning, but right now I think it's most important to have your colors available early.  We should be making land drops each turn into the late game.  I'm not all that worried about running out of basics.  By the time a 3rd Field of Ruin is cast, we should have enough card advantage that we're ahead or even on land drops.

MAYBEBOARD

Grandmaster of Flowers

I keep thinking that against a Green deck that isn't going that wide, a 4 mana walker that stops an attack and eats some damage could be really good.  A 7/7 Flying Indestructible dragon sounds like a pretty darn good wincon alongside Doomskar and spot removal as well.  Teferi is likely correct to maindeck in this slot right now, but I think this guy could be worth a shot if Green ends up taking over the meta.  Even if the trigger gets Snakeskin Veil'd, he'll saving you 4+ life and getting a card out of their hand.  Might try cutting Emeria's Call for a one-of in the sideboard just to give him a test-run against green.