The first question that inevitably comes to mind when evaluating Kaust, Eyes of the Glade is: Why play this over Kadena, Slinking Sorcerer? Because Kaust and Kadena only share one color, they have very different tools, though they overlap in payoffs: card advantage and mana production
The only factors which could offset their playability are the drawbacks of enchantments in general, and an overly cautious power budgeting from Wizards which leave a lot of Rooms as Limited-only curve-toppers
Honorable Mentions Though these didnt make the cut, these are cards which made the meta more interesting the list includes Jamming Tower, Secret Box, Binding Mochi, Briar, and Legacy Energy
It starts off small, but as you deal damage and crank up your speed, it becomes an unstoppable threat with double strike
Geth, Lord of the Vault, is a six mana 5/5 with intimidate, so it can only be blocked by Black Creatures or Artifact Creatures