Modal spells (spells with different effects you can choose from) are great for many decks as they let you use different effects depending on the status of the gamestate
I expect people to try this alongside Craterhoof Behemoth in Standard, and you better believe itll show up in EDH, at minimum in every Kinnan, Bonder Prodigy deck out there, and many more places, too
Having a 4/4 flyer for 4 that immediately interacts with the game is fantastic
I am a fan, however, of Devastating Mastery against decks that might have a variety of tricky permanents, but overall I think Azorius needs access to instant speed removal to make a contender and a better choice than Dimir
When will you learn that your actions have consequences
I feel that WotC is coming closer to an ideal core set, and this is very much a step forward