Hall of the Teachers

Hall of the Teachers enters the battlefield
tapped.
{t}: Add {w} or {r}.
Whenever a creature with power 4 or greater
enters the battlefield under your control, you
may pay {2}. If you do, Bolster 1.
"Where would we be without the Ascension? We must
do for other worlds what the Visitor did for us."
— Gigaphos