Five Pebbles, Rotting God

Defender, ward {4}

When this creature enters, you get an emblem with "At the beginning of your end step, you get a rot counter. Then, if you have five or more rot counters, you lose."

At the beginning of each player's upkeep, exile the
top five cards of their library. You may cast any number of spells from among them without paying their mana costs.