The Harbinger of Oblivion

Begin the game with this card revealed.
Ascend (If you control ten or more permanents,
you get the city's blessing for the rest of the game.)
During each upkeep you get a fate counter.
When you are attacked or lose life, add a
fate counter. During your end step, exile
the top card of your library. During your upkeep,
each player exiles the top card of their library.
If you get 50 fate counters, and the city's blessing,
all players are eliminated and denied
win conditions.