U/W Flash was such a powerful deck that Reflector Mage was banned alongside Smuggler’s Copter. That certainly changed the way the decks were built, and its success dropped off a cliff. Oketra’s Monument decks have taken over and the flash angle fell away, but Hour of Devastation has brought some awesome instant-speed options to help put the deck back on the map.
Nimble Obstructionist looks like exactly the card U/W Flash wants. It’s a 3-power flying creature with flash for just 3 mana, so it has a lot of similarities to the Legacy staple Vendilion Clique. On top of that, Obstructionist can be cycled for value, cashing in on one aspect of what Disallow has brought to blue decks. Being able to counter an activated or triggered ability isn’t always important, but you have the option when it’s relevant.
Gideon, Ally of Zendikar is still legal. That’s hard for many Standard players to imagine. So many were sure Gideon was going to get banned as it crushed event after event, and even after 5 cards have been banned in Standard, Gideon remains legal. Play with it if you can.
Spell Queller allows you to play even more at instant speed. Being able to Queller a spell your opponent casts is a huge tempo swing, but now that you have Obstructionist to add even more power to the battlefield, if they pass in the face of 3 mana, you get punished no matter what you decide to do against U/W Flash.
On the non-Flash side of the spectrum, you have Thraben Inspector and Selfless Spirit as early drops. These are cheap, get in damage, and add value. Inspector is a good draw early and late, and Selfless Spirit protects your key creatures from removal and sweepers. Selfless Spirit to protect Spell Queller is a great feeling.
Archangel Avacyn continues to reward you for having mana open as the game goes later. Archangel Avacyn is a huge threat and can win the game on her own. Selfless Spirit lets you decide when you trigger an Archangel Avacyn flip, and she brings yet more protection for your creatures and life total.
Censor gives you a nice tempo option to counter a spell or cycle when it isn’t valuable. This helps you hit your land drops, hit your curve, and still disrupt an opponent.
Supreme Will is a massive addition to blue decks. Yet another spell to be cast at instant speed, Supreme Will gives you two fantastic options in one card. While Impulse and Mana Leak are both 2-mana spells, they’re very powerful 2-mana spells. Adding a mana makes them both weaker, but having both options together makes for a strong card. Playing around open mana when your opponent could have a counter isn’t that hard to do, but when they can still cash in that mana for card selection instead of losing it like they would if they just had Mana Leak, you’re in a tough spot.
U/W Flash may have lost some of its flashier cards, but it has even more flash spells to dominate the game at instant speed!