If you {brainstorm} on your opponents turn, and the 1st of the 3 cards you draw is a {temporal mastery} can you play it? Just curious because the ruling under {brainstorm} says that the drawing of the 3 cards and the puting the 2 from your hand on top of your deck is 1 thing, and nothing can happen in between.
yes you can. you just have to keep temporal mastery revealed through out the process and you may cast it as soon as brainstorm resolves
Just make sure to keep the first card drawn separate from the rest of your hand while resolving {Brainstorm}