Mono-Blue Aggro has surged in popularity recently, and for good reason: it's a strong, punishing deck. The gameplan is simple: play cheap creatures, hopefully put a Curious Obsession on one of them, and back it up with countermagic. There isn't that much spot removal being played, making Mono-Blue Aggro look even better. It is one of the best choices to fight Sultai Midrange, and any slow blue deck is also quite favorable for mono-blue. The list I am playing is one that has become quite popular on MTG Arena, as many top Mythic players can be seen playing it:
Being a mono-colored aggressive deck, it is fairly streamlined. There really aren't that many debatable slots in the maindeck. Even the Blink of an Eye has had its moments. We saw in the games how each piece is super important, and games that don't involve Curious Obsession are a bit more of a struggle. Any big mana deck is a good matchup for Mono-Blue Aggro, as the chance a card like Pelakka Wurm actually resolves against you is pretty low.
The deck isn't easy to play. I don't think I navigated the games perfectly—far from it. Many of the decisions are about percentages, and it is easy to have a results-oriented mindset, especially after losing a close match. Many times the decision is between whether to tap mana on your mainphase or hold up countermagic, and these are going to be situational judgment calls.
The sideboard card I have been most impressed with is Entrancing Melody; stealing opposing creatures is pretty great. Surge Mare is there mostly for red aggressive decks, where the five toughness is going to be quite relevant. Faerie Duelist is what you are looking for against one-toughness creatures, as it can certainly take the opponent by surprise.
I expect to see a lot of Mono-Blue Aggro moving forward. The deck is easy to build and very good. It should be a good percentage of the metagame at the Mythic Championship in Cleveland after having a really strong week. The best way to combat this deck is more cheap removal, so we will have to see if the Standard metagame can adapt to the rise in popularity of mono-blue.
Thanks for reading,