Tome of Hidden Secrets

Tome of Hidden Secrets enters the battlefield
with 3 Mystery counters.
As long as there are 3 Mystery counters on Tome
of Hidden Secrets, remove a counter from it when
a non-token creature dies. If there are 2 counters
on it, remove a counter from it whenever an
opponent discards a card. If there is 1 counter,
remove a counter from it whenever a player loses
more than 4 life.
When the last counter is removed from Tome of
Hidden Secrets, draw 7 cards.