Abstract Nightmare

All players discard the top X cards of their library, then each player repeats this 4 more times.
If you have cast 3 or more spells before casting
this, then each player creates an X/X blue black
red legendary token creature named, Your Worst Nightmare that has, "When this creature enters
the battlefield, choose an opponent. That player chooses one: This creature deals x+x damage to
it's controller, where x is this creatures power, or
mill the top x+x cards of your library."