Essence Reclamation

Ascend (If you control ten or more permanents, you
get the city's blessing for the rest of the game.)
When Essence Reclamation enters the battlefield,
exile all creatures from your graveyard, then
create that many light tokens. (It's an artifact with "Sacrifice this artifact: Choose a color. Target creature
gains protection from that color until the end of turn.")
As long as you have the city's blessing you may
cast creatures exiled by Essence Reclamation.