Activate Phyrexian Devourer's second ability by exiling the top card of your library, causing you to put a number of +1/+1 counters on Phyrexian Devourer equal to that card's mana value.
Repeat step 1 until Phyrexian Devourer's power is greater than each opponent's life total.
Phyrexian Devourer's first ability triggers.
Holding priority, activate Jarad by paying ({1} magic symbol) ({B} magic symbol) ({G} magic symbol) and sacrificing Phyrexian Devourer, causing each opponent to lose life equal to Phyrexian Devourer's power.