Nebula of Seers

At the beginning of your end step, if Nebula of Seers is untapped and you control at least three tapped creatures, put a Vision counter on Nebula of Seers.
{t}: Add {c}.
{t}, remove a Vision counter from Nebula of Seers: Add {g}, gain 2 life, and scry 3.
"The stars are wiser than any mortal."