Creatures
Wall of Omens: Card advantage and early block
Knight of the White Orchid: Ramp (circumstantial) and devotion for Nykthos, Shrine to Nyx. It's also an effective blocker and early game beater, with first strike allowing it to win against a lot of early-game creatures.
Emancipation Angel
: 3/3 flyer for . Use it to bounce creatures such as Wall of Omens or Knight of the White Orchid and generate more value.
Archangel of Tithes: Low cost, high value - you get a 3/5 flyer, which also works as a Ghostly Prison, can prevent your opponent from blocking and at adds 3 devotion to Nykthos, Shrine to Nyx. Additionally, it's not a legendary creature, meaning you can have multiple of these on the battleground at the same time.
Gisela, the Broken Blade: Bruna, the Fading Light + Gisela, the Broken Blade
= Brisela, the Voice of Nightmares, and even though Gisela, the Broken Blade s susceptible to a Firebolt, you get a lot for 4 mana.
Baneslayer Angel: Big-beater-clock that keeps you alive. It also serves as a removal sponge, since thiss is a card your opponent will have to remove one way or another, making it easier for you to drop the heavier angels.
Thalia's Lancers: For tudoring up any legendaries including Nykthos, Shrine to Nyx.
Linvala, the Preserver: Very good at getting you back into the game, in case you're behind on HP or creatures.
Bruna, the Fading Light: As said before Bruna, the Fading Light + Gisela, the Broken Blade
= Brisela, the Voice of Nightmares. Her reanimation effect is also rather sweet, should you happen to have an Iona, shield og emeria lying in your gravyard (or any other big angel).
Akroma, Angel of Wrath: Finisher, gets around a lot of stuff, and with a ridiculous kit. Also a good plan B if you're having a hard time getting rid of a planeswalker.
Avacyn, Angel of Hope: Great finisher - prevents all you stuff from being destroyed, suddenly making Wrath of God a one sided board wipe.
Iona, Shield of Emeria: It takes a lot of effort to cast her, but once you manage to get her onto the board, it's almost certainly gg.
Lands:
Nykthos, Shrine to Nyx: With a deck consisting of so many high-cost, high-devotion permanents, the deck must containt Nykthos, Shrine to Nyx, not only will you need it but it's also too good to exclude.
Emeria, The Sky Ruin: Easy to activate since the deck is monowhite and unless your opponent has any exile effects, the value of the reanimate effect is huge once you get to the late game.
Enchantments:
Oblivion Ring: Mostly used to maintain plainswalkers or key-pieces (for example Cranial Plating). Not that they do not eist, but the modern meta lacks a lot of effective enchantment removal. You can also use it in combination with
Emancipation Angel
to bounce Oblivion Ring, which can be very effective.
Sorceries:
Wrath of God: For board clear.
Instants:
Path to Exile: Best removal in the format.