Some of the most powerful decks in Magic’s history have been labeled aggro-control. While these two opposite designations in the same deck may seem counter-intuitive, the ability to get on the board early and then protect that advantage is an effective strategy. You could see this in Legacy Delver decks that would lean on Deathrite Shaman and countermagic to take over the game while the opponent faced too many threats to deal with in time. In Standard, this strategy has gotten popular over the past couple of weeks on Magic Online, and I believe that this is the biggest enabler:
Curious Obsession is an extremely powerful card, but it comes in an unassuming package. Now, the floor for Auras is really low, so the juice has to be worth the squeeze. When they kill your creature with an Aura on it, you get 2-for-1’d, and that’s the recipe for losing games of Magic. When they don’t kill a creature with Obsession on it, however, you’re the one generating card advantage, so the question just becomes: can you approach the ceiling more often than you hit the floor?
The single mana cost really allows this to happen, but it also requires you to build a deck with cheap, aggressive creatures. After the rotation, the number of cards at your disposal drops dramatically, but you will still have access to Siren Stormtamer. A 1/1 flyer for 1 is exactly the target you want for cheap Auras, but the fact that your Stormtamer can protect a creature carrying Obsession for a single mana is where its real strength lies. Countering a Settle the Wreckage is a huge bonus.
You need other cheap ways to protect your creature with Obsession, and you’re going to have a number of solid options. For just a single mana, you can use Dive Down to protect your creatures in combat or protect an enchanted creature from a spot removal spell. Guilds of Ravnica brings a number of new counterspells, but you already have Spell Pierce, and Wizard’s Retort is a great option if you’re able to get some cheap Wizards into your deck to pair with your Stormtamers.
If you’re going with the Retort plan, Merfolk Trickster plays well with Obsession. It’s a cheap creature, it’s a cheap Wizard, and it will even tap down a blocker to force through more card draw.
This aggressive pressure has been a nightmare for someone like me to play against with my Turbo Fog decks on MTGO, and it looks like they’re not going anywhere with the rotation. There are a bunch of great new tools coming with Izzet, and a mono-blue strategy featuring Tempest Djinn is still a force to be reckoned with. I love everything Curious Obsession does and I expect it to remain a real player once we lose Kaladesh and Amonkhet blocks!