Protection from everything might not mean much on a 10-drop creature like Progenitus, but granting that same level of protection to a player for a full turn cycle is down-right silly, and exactly the reason you see The One Ring in just about any format where it's [questionably] legal
This card is so much more powerful than other options for draw in Blue, and also has the game revolve around it
Now let's turn to mass removal instead of targeted, like Chandra above
For example, Library of Alexandria is on the Reserve List as it was eligible due to the rarity rules of the List at the time (normally uncommons would not have made it)
Archmage's Charm has some versatility, but since it costs three blue mana, that pretty much limits it to mono-blue decks
Lorehold (RW), Prismari (UR), Quandrix (GU), Silverquill (WB), and Witherbloom (BG)