There's no argument that xBlue Aggro has been a staple in Pauper for many years now; however, similar to shifting seas themselves, this archetype is flexible, fluid, and furtively threatening. For anyone that has followed the broad Pauper meta-game for any length of time, you'll know that Mono U Aggro - sometimes known as Deep Hours Aggro - has been one of the most reliable mono-colored decks in the entire format. With its interactive onslaught from creatures such as Ninja of the Deep Hours and Faerie Miscreant, and its ability to lock you down with numerous counterspells, including the wildly popular Deprive/Mystic Sanctuary lock, there are few weakness to exploit. That doesn't mean there is no room for change, or a bit of personal flair, while remaining competitive.
If it ain't broke, then don't try to fix it. Pish posh, I say!
Shortly after Throne of Eldraine brought us Mantle of Tides, Mono U lists surged in popularity and power. In any and every format, Islands have never had a problem turning sideways for card advantage, but since this beat-stick hit the market, you are rewarded with creature buff for doing things that are just slightly unfair.
All that said, there has been an influx of varying Mono U lists as of late. Each one is a little different from the next and due to the nature of Magic's broken color, even the performance of identical lists will be just as varied. The following list, from a fellow Pauper addict, shows just how aggressive this normally-dawdling, control archetype can be.
Mono Blue Mantle - by H0L0cr0nHunter16
With enchantment removal in short supply in Pauper, Sunken City has resurfaced as a powerhouse in any sort of mono-blue list. If you count Winged Words as having a CMC of 2, this deck runs exactly zero spells that cost you more than a single blue and a colorless. With that amount of mana available, by turn 4, or so, paying the upkeep on this blue Crusade isn't a problem. Granted, it gives all blue creatures +1/+1, but that becomes easily remedied after some well-timed bounce spells, or a few clever sideboard maneuvers.
Between having fourteen flyers, and two unblockables, you could easily rename this deck Mono Blue Evasion.
It may seem like a fairly stock shell, but where this deck truly shines is just how quick it drops Elusive Spellfist onto the board, then suits him up with Mantle of Tides. The Monk's trigger of becoming unblockable, after casting one of your 26 non-creature spells, makes it an imminent and dominant threat. Considering that there are 20 spells in this deck that draw you an extra card, or more, it's rather easy to pump the Spellfist to 3, 4, 5+ power the turn Mantle hits the board. Even if your opponent's creatures are benefiting from Sunken City, they will pose little resistance to a giant, unblockable fist to the brain-box. Add to all of that the Mystic Sanctuary bonus of tutoring your graveyard, your draw spells just grew significantly. It helps to pick and choose which counterspell to top-deck, as well.
Until you can get your Tidy Monk swinging in for some action, you should consistently have a grip of control and other threats at your disposal. Faerie Miscreant and Faerie Seer provide the perfect, advantageous ammunition for Spellstutter Sprite to keep the path clear for one of your many flying creatures, including an easily-flipped Delver of Secrets. If and when your opponent is able to land a threat of their own, Vapor Snag and Blink of an Eye provide the right amount of cheap spice to set back a lot of strategies you may face. In the event that you run into one of the many go-wide decks that are currently rampant, Echoing Truth can be a life saver by providing an extra turn or two for your counters and Spellfists to work their magic.
This deck has so many options, and a seemingly endless amount of answers - in the form of beaters, buffers, and counters - that it will rarely play the same way twice in a row. Much like the more well-known Mono Blue decks in the meta, this takes a surprising amount of strategy to time your moves successfully, but at the same time, it has just enough aggro that it maintains a high level of speed. And to me... speed and strategy are two key factors in any deck.
Based on the recent, legitimate spoilers, Theros: Beyond Death looks to provide even more Pauper options to this most powerful slice of the color pie. In the meantime, let us at LSG know what you would do with this list. Thanks for reading!