Cards like Scute Swarm or Rabble Rousing can put so many creatures on board that your opponents won't be able to defend against a giant Devilish Valet
Heal Thyself: Number 49: Fortune Tune heals the controller's LP by 500 during each of their Standby Phases
Red Yellow Belo Betty Red Yellow Belo Betty has also slipped in popularity, particularly as many players are turning to Red Rayleigh for a more streamlined, aggressive strategy
I found it so because I was playing Dimir Rogues, a deck that relies on evasive creatures with flying that had a somewhat hard time beating other aggressive decks
I say this because its difficult to surmise some of the inclusions where flex slots exist, such as Forbidden Crown versus Forbidden Droplet, or something like Saryuja Skull Dread in the Extra Deck as a means of de-clogging multiple spare GMX Monsters or Oviraptors from your hand
These cards provide the elemental backbone for your strategy