Sacrificial Chamber of Exar Ku

Whenever a creature dies, put a dark aura counter
on Sacrificial Chamber of Exar Ku.

At the beginning of your endstep, target player may
have you draw a card and gain X life where X is
equal to the number of dark aura counters on
Sacrificial Chamber of Exar Ku. If that player
doesn't, you mill X cards and they lose X life where
X is equal to the number of dark aura counters on
Sacrificial Chamber of Exar Ku.