Standard is a format where you can take a couple key cards or interactions that fit well together and take them in almost any direction you like.
Archangel Avacyn and Hangarback Walker are a great place to start. Both of these cards provide raw power on their own and are incredible in combination. As a way to trigger Avacyn on turn 5 with a 0-mana investment, this potent combination can wipe the board of all Humans, Tokens, and whatever creatures Rites or Company decks spit out.
Gideon, Ally of Zendikar has proven incredibly challenging for many decks in the format to deal with to the point that it has defined deck construction. While some feared that Gideon would match up poorly against cards like Archangel Avacyn, creating a token before plus’ing Gideon and getting in for a ton of damage or creating an emblem still gives you a great board state. Secure the Wastes is still as good as it gets when you have a Gideon emblem, and triggers Westvale Abbey when you don’t.
So where to go from there? We’ve seen GW Tokens utilize all of these weapons already, but what about a simple UW deck? Thraben Inspector was initially included in WG Token builds, mostly as a way to turn on Dromoka’s Command. With access to Ojutai’s Command, getting an Inspector into the graveyard can be pretty awesome. This also turns Jace, Vryn’s Prodigy into a real threat that can be brought back at instant speed. While there aren’t too many spells to flash back, as Ojutai’s Command, Secure the Wastes, and Declaration in Stone are the only main-deck targets, Jace is still a tool to help get you your Archangel Avacyns and Gideons to finish the game.
Oh. Reflector Mage. Yeah, that one is pretty good too. I’m always happy to find a nice way to include some Reflector Mages!
The final benefit of blue is what blue always brings to the table—sideboard countermagic! Being able to stop big spells, especially in a world of The Great Aurora, is pretty nice. Countering Tragic Arrogance and Collected Company may be the first goal, but I’ve never turned away having extra answers.