The Matrix

When The Matrix enters the battlefield start a
Magic Subgame using your remaining decks as
your decks then exile all non-artifact creatures
and return them to the battlefield in the subgame
(all creatures that are not artifacts).
After each player takes a turn move both of your
decks to the other game and play that one.
At the beginning of each players upkeep
that player must sacrifice artifact creatures equal
to the number of artifact creatures they control
minus the number of creatures