Cavern of Knowledge

Cavern of Knowledge enters the battlefield
tapped
{t}: Add {u}
When Cavern of Knowledge enter the battlefield
if you control ten or more wizards you may
put target wizard with mana value three or less
from your graveyard to the battlefield.
"If you listen closely you can hear the wizards of
past whisper to those of tomorrow."
—Wendell, Wandering Wizard