Math Class, Bane of Students

At the beginning of each end step, put a time
counter on Math Class, Bane of Students.
-Remove a charge counter from Math Class: Each opponent discards a card or puts the top 3 cards
of their library into their graveyard.
-Remove 5 charge counters from Math Class:
Each opponent puts the top X cards of their
library into their graveyard, where X is their life
total. Then, each opponent who has a higher life
total than number of cards in their library loses
the game.