Reveillark

Flying
When this creature leaves the battlefield, return up to two target creature cards with power 2 or less from your graveyard to the battlefield.
Evoke {5}{W} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Field of Souls

Whenever a nontoken creature is put into your graveyard from the battlefield, create a 1/1 white Spirit creature token with flying.

Thermopod

{S}: This creature gains haste until end of turn. ({S} can be paid with one mana from a snow source.)
Sacrifice a creature: Add {R}.

Ashnod's Altar

Martyr's Cause

Sacrifice a creature: The next time a source of your choice would deal damage to any target this turn, prevent that damage.

Hofri Ghostforge

Spirits you control get +1/+1 and have trample and haste.
Whenever another nontoken creature you control dies, exile it. If you do, create a token that's a copy of that creature, except it's a Spirit in addition to its other types and it has "When this token leaves the battlefield, return the exiled card to its owner's graveyard."

Fanatical Devotion

Sacrifice a creature: Regenerate target creature.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Quintorius, Field Historian

Spirits you control get +1/+0.
Whenever one or more cards leave your graveyard, create a 3/2 red and white Spirit creature token.

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Karmic Guide

Flying, protection from black
Echo {3}{W}{W} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, return target creature card from your graveyard to the battlefield.

Goblin Bombardment

Sacrifice a creature: This enchantment deals 1 damage to any target.

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Spawning Pit

Sacrifice a creature: Put a charge counter on Spawning Pit.
{1}, Remove two charge counters from Spawning Pit: Create a 2/2 colorless Spawn artifact creature token.