There are many flavors to Approach. U/W was a reasonably popular option last season, but Esper and even R/W decks have made a pretty big splash since the rotation and bannings. B/W doesn’t have blue’s countermagic and card draw, but black can fill in some of those gaps. With the best removal in the format and better mana, B/W Approach could be the future.
Approach of the Second Sun is a great win condition. It can’t be interacted with easily and doesn’t require you to waste any additional slots in your deck. Drawing 1 copy means you’ll draw that some copy again in a handful of turns to win the game, and playing an Approach deck allows you to be creatureless for some fantastic game-1 matchups against dead Fatal Pushes, Vraska’s Contempts, and tons of other removal spells people are forced to play thanks to aggro.
Mastermind’s Acquisition gives you a tutor effect to find Approach when need be, or anything else you may be missing. With cheap removal, card draw, and access to sweepers, this can be a valuable tool. Note that you have an Approach in your sideboard, so if the opponent manages to use Lost Legacy to exile your Approaches, you can still go find the 4th to win the game.
You want removal? This is the deck for you. If they have early threats, you’ve 4 Fatal Push, 3 Moment of Craving, and 2 Baffling End to make sure that your life total is never under any serious pressure.
If the opponent is playing a slower game, you’ve got answers for bigger threats. Vraska’s Contempt can handle indestructible creatures and planeswalkers alike, as can Ixalan’s Binding while potentially shutting down from the same future threat. Doomfall is a fantastic weapon to exile a big threat or clear the path by disrupting your opponent’s hand.
Too many creatures on the board? You’ve got sweepers. A pair of Fumigates can wipe the board while gaining life, and you have 3 Settle the Wreckage to give you more answers to go-wide strategies, Gods, and even Carnage Tyrant.
With the board staying relatively clear, you need a way to gain your advantage before Approach can win the game. Renewed Faith is nice to gain a bit of life when cycling or buff you by 6 life points in a pinch, but it’s not steady. Treasure Map gives you some scrys and some midgame ramp and card advantage, which can be excellent. Arguel’s Blood Fast uses all of that life gain and rewards you for keeping the board under control. In control matchups, this can get you far enough ahead on cards that all your dead removal doesn’t hurt so bad! Arch of Orazca gives you yet another use for your extra mana to turn it into cards and really punishes an opponent for not making you spend mana to deal with threats.
B/W Approach is a nightmare for any deck that relies on creatures to win the game. With a win condition few players can interact with and every removal spell in the format, B/W Approach looks spicy!