As soon as I saw Settle the Wreckage

Most decklists we've seen have been straight U/W, accepting some of the weaknesses of the color pair in exchange for near-perfect mana and access to utility lands like Ipnu Rivulet

I tested all of these shells during Ixalan Standard and ultimately decided that Esper is the best option, and a couple of additions from Rivals of Ixalan have me convinced that this remains the right choice.

Esper Approach

4 Fatal Push
3 Censor
4 Disallow
4 Supreme Will
4 Glimmer of Genius
3 Settle the Wreckage
2 Fumigate
3 Approach of the Second Sun
2 Vraska's Contempt
2 Search for Azcanta
1 Moment of Craving
2 Torrential Gearhulk
4 Drowned Catacomb
4 Glacial Fortress
4 Fetid Pools
4 Irrigated Farmland
3 Aether Hub
2 Field of Ruin
2 Island
1 Swamp
2 Plains

2 Azor's Gateway
2 Deadeye Tracker
2 Duress
2 Forsake the Worldly
2 Moment of Craving
3 Negate
2 Nezahal, Primal Tide

The Manabase

Let's get this out of the way first:

Where's Concealed Courtyard

? How are you casting Fatal Push

on turn 1?

I'm not, and it's not realistic to expect that you could. What I am doing is playing a tap land - usually a Fetid Pools

Field of Ruin

The manabase is very blue-heavy, but the black and white sources are sufficient given the amount of card draw present.

New Additions from Rivals of Ixalan

Azor's Gateway

Once transformed, Sanctum of the Sun provides a large amount of mana every turn, which can close games very quickly. It doesn't fuel Search for Azcanta

The deck contains cards with eight different mana costs, making transformation of the Gateway very achievable.

Moment of Craving

In a control mirror, your opponent is likely to be sitting back on their counterspells waiting for you to try to win the game. Enter Nezahal, Primal Tide

The Resurgence of Torrential Gearhulk

Speaking of our old friend, this is, in large part, a Torrential Gearhulk

Instead of enchantment removal like Baffling End

Mapping Out Turns

For a creature or combo deck, it's relatively easy to figure out what your ideal draw might be. With a highly reactive deck like this one, what you do in the early turns is highly dependent on what your opponent does. However, we can still measure the success of a turn sequence by two metrics:

1. Mana efficency. The more mana efficient your turns are, the more effective you are likely to be.
2. Options. The more options available to you, the fewer options you will be able to make available to your opponent.

Let's walk through each turn and list our best options, in order of efficiency. For the purpose of this exercise, we'll assume we're making our land drops.

Turn 1

1. Play a tap land.
2. Play a Swamp or Aether Hub
   and cast Fatal Push
   . (rarely)

In my opinion, it's nearly always incorrect to cycle Censor

Turn 2

1. Cast Search for Azcanta
   .
2. Cast Censor
   or Fatal Push
   or Moment of Craving
   .
3. Cycle a land.

Again, usually we will find better things to do than to cycle Censor

Turn 3

1. Cast Supreme Will
   in Impulse
   mode.
2. Cast Disallow
   (or Supreme Will
   in Mana Leak
   mode).
3. Play a tap land and treat it like turn 2.

Already our options are expanding. We can slow our opponent, search for what we need, or cycle away an extra land.

In cases where we have both, the choice between Disallow

Turn 4

1. Cast Glimmer of Genius
   .
2. Cast Settle the Wreckage
   .
3. Cast Vraska's Contempt
   .
4. Cast Disallow
   or Supreme Will
   plus Fatal Push
   .

This is the turn where we try to make life difficult for our opponent. Playing around each of these options usually requires a different line of play, and you will often have access to two or more of these options on this turn.

Turn 5

1. Cast Fumigate
   .
2. Treat it like turn 4.

One of the costs of playing around Settle the Wreckage

Turn 6

1. Cast Torrential Gearhulk
   .
2. Cast two spells.

Turn 7

1. Cast Approach of the Second Sun
   .
2. Do something else.

As the decision tree is extremely wide at this point, let's shift from discussing how the game begins to how it ends.

Planning Your Approach

One of the keys to playing this deck is picking the correct turn to cast Approach of the Second Sun

The most common play pattern is:

1. Cast Approach.
2. On the next turn, dig seven cards deep.
3. On the third turn, cast the same Approach again.

This requires you to dig five cards deep between the first Approach turn and the second, not counting the two draw steps.

The main deck contains 14 cards that dig one card deep: Search for Azcanta

There are 10 cards that dig up to four cards deep: Supreme Will

Any combination of two of these effects, as long as one digs four cards, will find you to the second Approach in time to cast it two turns after the first one resolved. Depending on what's in your hand and on the battlefield, you will need between 3 and 8 mana for this. Whatever's left can be spent keeping you alive.

Yes, I counted Search for Azcanta

The Sideboard

In a wide-open metagame, versatility of sideboard cards is critical.

Azor's Gateway

Deadeye Tracker

Duress

Forsake the Worldly

Moment of Craving

Negate

Nezahal, Primal Tide

Looking Ahead

As the metagame shifts, it's important to make adjustments. Of course, the list can also be tuned to your local metagame.

Cards like Moment of Craving

Sweepers such as Settle the Wreckage

Whatever your maindeck configuration, make sure you have enough cards to bring in for control mirrors, where the majority of your removal spells will be blanks.

What do you think of this build? What changes would you make?