Spells like Opt and Behold the Multiverse are popular for scrying and immediate card draw at instant speed
That ended with a rules change regarding the cost of split cards, especially in situations where you could cast a spell with mana value X or less without paying its mana cost
Mulldrifter is very near and dear to my heart
Crucible of the Spirit Dragon might seem a little slow, but banking mana over several turns sets up some truly explosive plays, especially when your hand is full of huge, expensive creatures
(It attacks each combat if able and attacks a player other than you if able.) Whenever one or more Faeries you control deal combat damage to a player, that player creates a 4/2 red Pirate creature token with "This token can't block." The token is goaded for the rest of the game
In the first of the two set six decks, we see the combination of Ruby and Amber and many classic characters reimagined as swashbuckling, sword-slinging pirates