Sinister Concoction is mana-efficient hard removal that usually gets you all the way to delirium by itself
Launch the game and make it intentionally frustrating to progress and/or be incredibly stingy with free premium currency (or whatever is needed to do pulls/open packs) after the initial honeymoon phase
This is one of the best and most extreme implementations of sneak, but it takes the card from being a possible inclusion to a must-have for milling decks, and maybe even at three or four copies, too (in Standard)
This is a little bit clunky and you have to be careful about when you cast it -- but when the coast is clear, it's going to kill something and make your creature a better attacker at the same time
Curve Dragons tightly and include haste enablers so new tokens impact the board the turn they arrive
The ability to exchange one resource for another gives players plenty of choice on how best to use their creatures, lands, and spells to find winning combinations (more info on the theory behind that here)