Clash at Sparrow River

(A Skirmish enters the battlefield under your
protection. At the beginning of each upkeep, remove a defense counter from it. The player that removes the
last defense counter defeats it, exiles it and may cast it
transformed.)
Each player puts a nonland permanent they
control on the top or bottom of their library. For
each creature you controlled that left the battlefield this turn, create a 2/2 blue Illusion creature token.