Mystra, Mistress of Magic

Hexproof
As long as your devotion to blue is less than six,
Mystra isn't a creature.
At the beginning of your upkeep, scry 1. Then
exile the top card of your library. You may play
cards exiled this way without paying their mana
cost.
"I am the One True Spell at the heart of all spells.
There is no other."