Olivia can explode out of nowhere, completely flipping the battlefield and the course of the game
Decklist: 1 Orvar, the All-Form
Also of note: up to this point, most Auras entering the battlefield didnt have an enters the battlefield effect unless it was directly tied to what the card was doing (Sleeping Potion taps the creature when it enters in order to keep it tapped) or just a normal cantrip, which many spells in the game were doing
Ultimately, this has likely happened thanks to the new copies available via The List, however, its nevertheless a noteworthy point
While control decks typically leave a lot of mana on the board outside their own turn, this will raise alarm bells for your opponent, who may look to counter if possible
I often dislike dealing with cards that feel grimey and gross