Hallownyx, Luna's crossing.

(Snow-covered lands can be tapped to add {s} to your mana pool.)
Whenever Helios rises, you may pay {2}{s}{s}.
If you do, search your library for a Lunar
Snow-Covered Land and put it onto the
battlefield. Then shuffle your library.
{t}: Add {1} to your mana pool.
Moonlight- Whenever you control 5 unique Lunar Snow-Covered Lands, you win the game. You
can only win the game this way if Luna had risen.
But in the end, Luna's true blessing is her bridge.