Sanctuary of Mana

This spell costs {x} less to cast, where X is the
greatest power among creatures you control.

{t}: Add {g}{g}. You gain 2 life.

Whenever a nontoken creature enters the battlefield
under your control, put a +1/+1 counter on it and
draw a card.

"A forbidden and sacred place where the Mana Tree
is said to reside."