Arasta of the Endless Web, Rotwidow Pack, Hatchery Spider keep the spider army growing
Cards like Swords to Plowshares and Beast Within are super-staples of the format, and this gets you extra value when your opponent aims them at you
Thats a great finisher
4UBR: Exile Nicol Bolas, the Ravager, then return him to the battlefield transformed under his owner's control
Honorable Mention: Singularity Rupture Look, I know this article is supposed to just be about Azorius Control, but bear with me
I think the card really ties this deck together, being absolutely ridiculous with 1) Sylvan Library, by milling cards you dont need and allowing an easy draw two) and 2) flashback cards, by letting you get value out of milled cards