You could improve the mana base easily with things like Prairie Stream and Flooded Strand is relatively cheap currently. Also a Hallowed Fountain or two. Having fetch shock mana base just helps a lot also Azorius chancery makes you take a turn off which you want to avoid.

Perhaps have more taxing effects main deck and try some traditional removal and counters as well?

There is a lot that can be done in W/U. Best of luck brewing if you want more suggestions feel free to ask !

While I agree with you, I rather keep a large amount of plains cards for use with Endless Horizon. I also really like having Azorius Chancery as it helps me if I am low on mana cards in my hand.

I agree with Apakakuta. Keep in mind thatHallowed Fountain and Prairie Stream are plains and Endless Horizon never says the plains has to be a basic plains.

Thalia's Lancers might be a consideration it can fetch Augustin, several angels, and nykthos

I see you are considering Enchanted Evening. Keep in mind that when combined with Starfield of Nyx would cause all your lands to be a 0/0 and immediely be put into the graveyard as a state based action. Just something to be mindful of.

Thank you Firebones675! I did not make those connections. Beyond being able to draw Hallowed Fountain and Prairie Stream with Endless Horizons, is there any other bonuses to using them over Glacial Fortress? I didn't want this deck to cost an absurd amount of money and those special lands are a little expensive. Same reason I didnt jump for Greater Auramancy. Quick question, if I use Endless Horizons and it gets destroyed, do I lose those plains? I would assume I would but I read something weird about how it resolves somewhere. I wanted to put enchanted evening in to prevent players from using cards like Spring Cleaning but I did not realise I would destroy my own lands. Does any one else have other ideas to prevent enchantment board clear cards? Thank you for commenting!

Using glacial fortress instead would be fine. With regards to the lands the main reason why they are more expensive is because of fetchlands/shocklands. In a hypothetical white/blue/green deck, A single copy of Flooded Strand can find Hallowed Fountain, Breeding Pool or Temple Garden (in addition to finding regular basics) which is really helpful to make sure you always have each of your colors. In a two color deck this becomes a little less important since Glacial Fortress already gives you both of your colors. The main dowsnides to running fortress is if you draw an opening hand with 4 copies of fortress, they would all be forced to come in tapped compared to a shock/fetch mana base. Also as i mentioned earlier because they have a basic land type they can interact with cards like horizons. (Technically there are a couple other reasons like being to be able to shufle your library at will or thinning your deck slightly but that likely won't come up in your deck)If that's fine with you, running with the fortress mana base instead isn't bad by any stretch and significantly cheaper.

As for your horizon question, what happens when you cast it is that that specific copy of the card exiles the lands. If it leaves play for any reason the lands stay exiled. If another copy is played (or even the same one you played originally) the game sees it as a new card and thus can't choose any of the plains you exiled originally.

The specific wording on magic oracle is as follows (If your not familiar with the site you can google mtg oracle. It has every card ever printed and additional rulings for them)

1)If Endless Horizons leaves the battlefield, the remaining Plains cards stay exiled. If Endless Horizons returns to the battlefield, its a new object with no relation to its previous existence. The previously exiled Plains cards will still stay exiled.

2)If a different player gains control of Endless Horizons, its ability will trigger at the beginning of that players upkeep, but it wont do anything when it resolves.

Hope this helps!

I really like your deck, keep up the good work! My suggestion is to move mainboard Rest in Peace, maybe replacing some graveyard hate, because graveyard hate can stop Snapcaster Mage, Tarmogoyf, Grim Lavamancer, Dredge, Delirium and Delve strategy, while Stony Silence is rarely as useful if you are not against affinity.

Leyline of Sanctity is also a card which probably deserves more than one slot, because it saves you against Burn and protects your hand from black discard. If budget is a problem, Ivory Mask or Aegis of the Gods are suitable replacements. Against Burn, Nyx-Fleece Ram is another great card, giving you life and blocking every creature they have.

Eidolon of Rhetoric is a good sideboard card against Storm and is both a creature and an enchantment.

Then Dovescape is a card in your colours that can protect your permanents and become an alternative win-con if you counter your not-needed enchantment. But is more of a fun card than a necessity.

Thank you! The description is still undergoing some work and it requires some tweaks in some places. I agree that I should pop Aegis of the Gods in there, I actually have it in a enchantment creature commander deck and was considering it for a while. Ivory Mask, itself was actually traded out for Leyline of Sanctity. Rest in Peace is great, but the problem is that I use Monastery Siege khan's into a Open the Vaults for a win condition. So exiling cards from the graveyard kind of hurts that. If there is a way to stop cards in the opponent's graveyard, I would consider that.

As for Nyx-Fleece Ram I gain life every time an angel enters the battlefield. I dont generally have an issue with that. I just made a change, I am swapping out Oblivion Ring for Journey to Nowhere mostly for increased defence against early aggro decks.

My bad, i forgot about Open the Vaults.

Nah I am just glad to get comments!

Is there something like Nihil Spellbomb for enchantments?

You mean an enchantment which mess just with your opponent's graveyard? Leyline of the Void is a thing, but it isn't in your colours.

Well, true and close but not quite that either. Nihil Spellbomb is only the opponent's graveyard. If there was an enchantment that did the same thing I would include it.

Well, Leyline of the Void targets just your opponent's graveyard. The problem is that it doesn't remove what it's already in their graveyard.

These are nice, but they are in black. http://gatherer.wizards.com/Pages/Search/Default.aspx?text=+[Exile]+[from]+[target]+[player%27s]+[graveyard]&type=+[Enchantment]

Yea thats too bad

Tormod's Crypt instead of Nihil Spellbomb Because you can't pay the black so it is strictly better

Thanks darklord1135!