My theorycraft comments:
What is Land Tax really doing for you in this build? Yea, if it goes off a few times you thin all of the plains out of your deck, but how relevant is that? You have no way of abusing extra cards in your hand.
I don't like maxing out on Serra's Sanctum. It is a pretty sweet T1 play with some Leylines, but you never ever want two in your opening grip. Three seems like a better number to minimize mulligans.
I've seen people try to use Heliod, and I just don't see it. He's expensive and hard to turn on, and when you do, your payoff is just a dork that eats Swords to Plowshares or gets bounced by Jace.
What's wrong with branching out into a second color? Blue gives you Thassa, who is a superior God to Heliod. Black gives you the ability to hard cast your second Leyline and cards like the Abyss. Red gives you Seal of Doom, green gives you Seal of Primordium...
I disagree that you should run less than 4 Serra's Sanctum. It'll likely get wasted early so you want that second one to be available pretty early.
I think Heliod could potentially be the wrong choice, but do you have a better idea for a finisher that is ALSO and enchantment or would work well in the deck? This guy costs 4 and can't reliably be killed except by Swords (I have 4 Spirit Of The Labyrinth to hopefully deal with Jace as well as 4 O-Ring). To me that seems like a pretty hearty win-con that doesn't require support cards to be good. Just mana.
Thassa could be a good justification for a splash color but I'd really like to be able to get to 5 blue devotion and not just have to use her for her other abilities. This would require a departure from white that this deck doesn't want for obvious reasons (Serra's Sanctum only adding white mana is a big one).
As for Seal of Doom I just don't get how that is any better than O-Ring. It's a lot worse in most scenarios. It doesn't deal with BSC or Bob and it can't remove an Oath, Jace, Crucible or Smokestack the way O-Ring can. O-Ring is a catch all card in our colors so it doesn't exactly make sense to branch out to a second color for an inferior card. Now, if there are other niche cards in other colors that ARE superior I am all ears, but that ain't one of 'em. City Of Solitude intrigues me out of green as does Sterling Grove and Trace Of Abundance (If I ran Trace I could THEN be persuaded to run 3 Sanctums as they wouldn't be able to be wasted as often).
You may be correct on Land Tax, but in a mono-white build I don't see how Land Tax isn't a huge help. Deck thinning is no small thing when your deck has no REAL draw engine. Also, assuring yourself land-drops against shops is no small thing. I also like the fact that land tax is a turn 1 play that helps ramp up your Sanctum. Do you know of any other 1-drop white enchantment that could take its place? Is the only option to go to green for something like Root Maze? I'm curious to hear alternatives to Land Tax, because it is also the most "what?" sort of card to me as well. It just seemed to fill a role I needed to I included it. So, thoughts?
I hope this answers your questions.
-Storm
