The first enchantment creature was Lucent Liminid from Future Sight
If that winds up in your graveyard, Yuna can summon it to the battlefield
If you're counting on Winged Sliver or Muscle Sliver or any other boost to carry you through combat, then a removal spell on the key ability can destroy your entire team, and even with Hibernation Sliver available such a blow is often crippling
We'll have the nitty-gritty below for those who like details, but for a quick look at how Theros Beyond Death Collector Boosters are bringing Theros to life, well, here you go: And, for the detail oriented, here's a less-pretty bullet-point list for what contents can fall in which slots
The other preview, for Through the Ages, is Wall of Omens, rendered as The Imperial City of Archades
Ahead of Ursula's Return releasing later this May, Screen Rant previewed both Starter Decks and played them against the Starter Decks from Into the Inklands and The First Chapter to test them out