There are plenty of Reserved List cards in this set, but fewer than The Dark , with its larger print run and less than $1,000 total cost
Goblin Wizard Goblin Wizard beats out Warren Instigator and Goblin Lackey by simple virtue of not having to attack and risk its life for that extra free goblin
That might be Luminarch Aspirant or Innkeeper's Talent just spicing up your Cube deck with some extra power, or it could be a dedicated build-around seeking to exploit Winding Constrictor and Ezuri, Claw of Progress
A common bad position against Rakdos is be on the draw, they play Bloodtithe Harvester on two, I play Caryatid, they attack, I take 3, they play Fable
And if that's not enough, she has partner so you can choose the most powerful adjunct colors and concepts
Efficient flying Dragons are almost always must-haves as late-game finishers, and Realm-Scorcher Hellkite has a few extra tricks to make it even better