Cassandra, Prophet of Doom

{2}{u}{u},{t}: Scry 4. If your devotion to blue
is less than 5, draw 4 cards, then discard 4 cards. (Each {u} in the mana costs of permanents you control counts toward your devotion to blue.)
"Have I missed the mark, or, like true archer,
do I strike my quarry? Or am I prophet of lies, a babbler from door to door?"