Mortify
.
Assassin's Trophy
.
Deafening Clarion
.
Ionize
. Any multicolored planeswalker.
Angrath's Rampage
? Oh, well, that one still works, but we have
Leyline of Sanctity
in the sideboard for it, don't we?
Stonecoil Serpent
is a generally excellent card in any midrange deck - an efficient body for something with reach and trample, and the ability to come in whenever for whatever mana you want to pay make it playable basically anywhere - but where it really shines is its unique protection from multicolored, which makes many of the best removal spells in Standard, as well as most planeswalkers, completely unable to deal with it.
All That Glitters
buffs the snake in a way that's pretty powerful on cast while still scaling (get it? scale-ing?) into the late game. With
Scuttlemutt
, which can make things
Stonecoil Serpent
doesn't like multicolored and doubles as a mana rock with a body, the Serpent is really hard to deal with, and if it does get removed, there are three more in the deck to take its place.
Of course, you need to be able to actually sift through your deck to find these things.
Witching Well
is a lovely one-drop artifact that helps with that early on,
Eyes Everywhere
is great in the mid-game, and both beef up
All That Glitters
, which is pretty key.
Arcanist's Owl
is pricey at 4, but it gives you a 3/3 in the air and it's basically the premier way for a deck like this to find what it needs to find. The only cards in the deck it can't actually dig up are
Dovin's Veto
, just such a good counterspell that no self-respecting Azorius deck should be without a playset, and your four nonartifact creatures, three
Shinechaser
for what's nearly always an evasive 3/3 with vigilance for 3, and a single
Emry, Lurker of the Loch
.
What else is left? Utility and removal!
Frogify
is nearly always better than
Pacifism
in this list, since it strips the target of its abilities, and a 1/1 chump block isn't going to do much against your fliers or your trampling Serpents.
Conclave Tribunal
is a very useful catch-all removal spell, and
Manifold Key
can get one of your owls or snakes back as a blocker, untap
Scuttlemutt
for more devious scarecrow things, or sneak a heavy hitter in for the win in the late game.
Last but not least, the sideboard should be pretty straightforward. Leyline of Sanctuary, as long as it's unbanned, is a pretty automatic pick for any deck running white, and it's especially good in an enchantments matter list like this one.
Portal of Sanctuary
is our response to removal,
Disenchant
can deal with our opponent's artifacts and enchantments, and
Time Wipe
is a great board clear that ignores
Stonecoil Serpent
. The sideboard should also help you curve out later in slower games, with
Shimmer Dragon
providing an alternate win condition that likes artifacts, and
Ugin, the Ineffable
giving you bigger Serpents faster, synergizing well with
Scuttlemutt
to remove colorless permanents, and just being a generally excellent card.