Lodestone Golem is restricted. Now, I know what you're thinking: Storm! Storm! Storm! That might be a bit premature, though. Fact is that critters that can't take on a 5/3 and live to tell the tale just got a lot better. So did very slow strategies that couldn't win given a one-turn break from the Golem. So let's talk about something we haven't talked about in a long time: Sullivan Solution.

The core idea is very simple: Erayo is a hard lock alongside a range of other effects. In particular, Arcane Laboratory is a great response to a combo meta. This struggles against critters, though. Luckily, a few printings have happened since then. We now have Mentor, Stoneblade, and Tasigur, and any of those three easily make the cut. So long as we can start and win a counter war or even just blitz out a bunch of spells, the game is pretty much over. The only caveat: we can't afford to lose on turn 1.

The core is clear:
4 Force of Will
4 Mental Misstep
1 Mindbreak Trap
4 Thoughtseize
4 Gitaxian Probe

1 Ancestral
1 Treasure Cruise
1 Dig Through Time
1 Time Walk
1 Demonic Tutor
1 Vampiric Tutor

3 Erayo
3 Arcane Lab

1 Black Lotus
5 Moxes
15 Land

That leaves 8 cards to metagame. Thoughts?

Could you explain the relevance of theorycrafting for a meta game that not only does not exist but has potential for never existing?

It's seems more prudent to take preexisting tempo/control lists and tune them appropriately. Why settle for anemic threats when you can play Delver of Secrets, Young Pyromancer, Monastery Mentor , or Vendilion Clique? There's a reason why narrow builds like this went out of style in 2007.

I played this deck for a hot second before quitting magic back in 06, and was a big fan! Interesting that you have left the "metagame" slots to include the wincon. I understand that Arcane Lab +flipped errayo = a hard lock, but how are we winning from there? We can look at...

Jace VP - Great with 4 thoughtseize, demonic and vamp, makes flipping Erayo easier, turns into a wincon via milling eventually
Tinker/Blightsteel - Would need to add a mana crypt and maybe mystical tutor, but Dack Fayden may be at an all time low so this could look really good.
Vendillion Clique - Hand disruption fits the bill, and you can play it on your opponents turn which is nice with Arcane Lab.
Stoneforge/Batterskull - If you are working in a third color, Stoneforge interacts nicely with Arcane Lab and white opens you up to additional creature removal like swords and supreme verdict.
Spirit of the Lab - A pet card of mine, but really hammers home the lock down element, and it trades with a lodestone! (HA!) plus I noticed you left brainstorm off the list (accident I'd guess).
Notion Thief/Consecrated Sphinx - These sort of speak for themselves, If you are splashing Red you can do worse than Thief+Dack

There are many other options, but if i had to fill out the 8 Cards (and staying straight U/B) I would test:
1 brainstorm
2 Jace VP
1 flusterstorm
1 tinker
1 blightsteel
1 Mana crypt
1 Mystical Tutor
1 Board sweeper...Maybe Toxic Deluge?

You notice I have 9 cards listed...i would also consider shifting the ratio of thoughtsieze and git probes to include some number of duress. The life loss could become problematic in a long game.

As cool as this deck is, the printing of Abrupt Decay means that it is unlikely ever to be very good again. If no one is playing Decay, it gets better, though Decay gives decks the ability to adjust well to this

If you want to play 4 spells in a turn, I suspect 4 preordains and 4 gushes are the best approach. But then - arcane laboratory.

What about replacing laboratory for canonist, and play more artifacts? with 2 sensei's you are flipping erayo easily. vault + key would be an unnafected combo.

manlands is another approach and lets you win without playing lots of spells.

what I don't like is dimir cutpurse. lovely creature back in time, crappy nowadays...

@The-Atog-Lord Solid point. It's not clear how much of the meta would be running Decay, but it's a huge problem every time you run across it. You've invested a bunch of resources into something that's pretty cool, but only so long as it can't be answered. Running Misdirection seems like a poor response as it just doesn't do much anymore.

@socialite It's not controversial that Lodestone is restricted or that combo decks are likely to benefit from this. It's modestly questionable whether Gush or Dark Ritual benefits more. Either way, Arcane Lab is much better than it was. Good enough? Harder to say.

@p3temangus My thoughts were pretty similar. I think Mentor is also a potential inclusion since it benefits from playing many spells each turn. Red and maindeck Sulfur Elemental is interesting too, particularly if Thalia starts seeing more play.

@xouman Once you go the canonist route, you're letting them burn a mox to ignore the Erayo effect for a turn. 4 Preordain + 4 Gushes might favor just running Mentor since you're probably threatening lethal damage the next turn instead.

If you don't want to splash white, Thing in the Ice sounds solid here. It can bounce Erayo which is terrible, though. But as a 1-of, maybe?

The problem with Sullivan right now are both Abrupt Decay and the fact that the format is being played on the table more than the stack. So even if you flip Erayo, it's not the hard-lock it once was, because your opponent could've simply resolved a Delver, Pyro, Deathrite before that.

@AmbivalentDuck Curse of Exhaustion. Already a strong card by it's self and doesn't stop you from flipping Erayo. Imagine trying to win counter wars when you're limited to one spell per turn.

@Aaron-Patten 4 mana is so much, though. Do you really want this over Jace? By the time you're resolving 4 cmc spells, it's not clear that anybody still has much in their hand.

@AmbivalentDuck I can think of a few situations where you'd want it over Jace in an Erayo list. I wouldn't recommend playing more than one of it unless you're dedicated Curse of Exhaustion combo. I do think the card is playable but I have been wrong. It certainly seems good against Monastery Mentor, Young Pyromancer, Gush, and Storm.

gha. There was a thread on this on the previous Mana Drain; called blue prison, I think. The basic problem is you can't reliably flip Erayo without having a lot more moxes than average... at least 6-7 more (1 petal, 2 chrome, 3 opal, 1 mana vault). Then your manabase becomes really vulnerable. Second, Arcane Lab plus Erayo is also a non-bo if the Lab is played first; so we ended up cutting Arcane Lab. Third, you totally can lose to an early threat that comes down before Erayo flips; there's not really enough room left in the deck for a robust draw & tutor & answer package. 4th, its not clear this 2-mana enchantment is at all better than Oath of Druids. Finally, Arcane Lab probably is awesome in this meta, but a deck based around Eidolon of Rhetoric is probably a lot better.