The saga mimics two triggers from Umezawa's Jitte, which most of you have already heard of
In case these permanents got +1/+1 or -1/-1 counters while they were face down, those counters wont disappear after the cards are turned face up, but they wont do much as long as the permanents arent creatures
The reality is, many Book cards share this ability
Maelstrom Wanderer and Craterhoof Behemoth are top-end titans that can close out games in a hurry, while Archetype of Endurance and Dawnglade Regent make it harder to interact with your board
Key Cards Giada, Font Of Hope The commander of the deck, Giada, Font of Hope does just about everything you could want a commander to do
White also has ways to punish those who break the rules, such as destroying a creature if it becomes too powerful