Altar's Reap

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Ninth Bridge Patrol

Whenever another creature you control leaves the battlefield, put a +1/+1 counter on Ninth Bridge Patrol.

When Doomed Traveler dies, create a 1/1 white Spirit creature token with flying.

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

When Hunted Witness dies, create a 1/1 white Soldier creature token with lifelink.

Vigilance
Whenever another creature you control dies, you may transform Thraben Sentry.