It also has some interesting upgrade potential
You may cast any number of spells with mana value X or less from among them without paying their mana costs. This means you can cast anything, be it permanent or not, as long as youve put enough mana into it
It has definitely changed over time gone are cards like Snapcaster Mage and Street Wraith, which used to be considered staples of the archetype, and instead we see the deck utilize many of the best cards printed in the past two years such as Dragons Rage Channeler, Ragavan, Nimble Pilferer and Lurrus of the Dream-Den
Make a good stuff control deck based on blacks big mana (looking at you, [casthaven]Cabal Coffers[/casthaven]), include stuff like [casthaven]Conjurers Closet[/casthaven], and then point your effect at the blue decks to see if you can grab a counterspell
Superfriends decks (built around planeswalkers) use more.