While two mana for two cards each turn is definitely a good rate, there is a very real delay with Sylvan Library: it takes a whole turn cycle to actually do anything, which, as well see with the rest of the list, makes it fairly slow by comparison
You can only use this effect of "The White Stone of Ancients" once per turn
There are a bunch of different ways to abuse the card alongside Landfall triggers and sacrifice outlets, so it makes for a reliable alternate win condition in decks like Aristocrats
By being able to lock your opponent out of casting spells of any one colour when she entered the battlefield, Iona may as well have read "your opponent doesn't get to play Magic." Spark it: Read our beginner's guide to MTG Jumpstart In a Modern deck like Gifts Ungiven - where the eponymous card lets you put Iona into your graveyard only to reanimate her later - she can enter play on turn four, and close the game from there
It may have minor damage
And life was a bit bleak in a lot of stories because well, it was
