The Oblivion Worm

Trample

Whenever a card enters exile from anywhere, put a
+1/+1 counter on The Oblivion Worm.

At the beginning of each player's upkeep, that
player searches their library for a spell, exiles it,
then shuffles.

{w}{u}{b}{r}{g},{t}: Each player exiles the top card of
their library.