The List

Creature — Spirit

Sacrifice this creature: Target creature you control gains protection from the color of your choice until end of turn.
Soulshift 3 (When this creature dies, you may return target Spirit card with mana value 3 or less from your graveyard to your hand.)

Moonlit Strider

{G}{G}, Sacrifice this creature: Put target land on top of its owner's library.
Soulshift 3 (When this creature dies, you may return target Spirit card with mana value 3 or less from your graveyard to your hand.)

Rootrunner

Sacrifice this creature: Target creature gets -1/-1 until end of turn.
Soulshift 4 (When this creature dies, you may return target Spirit card with mana value 4 or less from your graveyard to your hand.)

Scuttling Death

Modern Masters 2015

Whenever you cast a Spirit or Arcane spell, target opponent loses 1 life and you gain 1 life.
Soulshift 2 (When this creature dies, you may return target Spirit card with mana value 2 or less from your graveyard to your hand.)

Thief of Hope

Salvat 2005

Flying, first strike
Soulshift 5 (When this creature dies, you may return target Spirit card with mana value 5 or less from your graveyard to your hand.)

Kami of the Palace Fields

Saviors of Kamigawa

Vigilance (Attacking doesn't cause this creature to tap.)
Soulshift 4 (When this creature dies, you may return target Spirit card with mana value 4 or less from your graveyard to your hand.)

Torii Watchward

Flying
{2}: This creature gets +1/+1 until end of turn. Sacrifice it at the beginning of the next end step.
Soulshift 1 (When this creature dies, you may return target Spirit card with mana value 1 or less from your graveyard to your hand.)

Deathknell Kami

Soulshift 3 (When this creature dies, you may return target Spirit card with mana value 3 or less from your graveyard to your hand.)

Kami of Empty Graves

Whenever you cast a Spirit or Arcane spell, reveal the top three cards of your library. Put all land cards revealed this way into your hand and the rest on the bottom of your library in any order.
Soulshift 2 (When this creature dies, you may return target Spirit card with mana value 2 or less from your graveyard to your hand.)

Elder Pine of Jukai

At the beginning of your upkeep, sacrifice this creature unless you pay {G}.
Soulshift 3 (When this creature dies, you may return target Spirit card with mana value 3 or less from your graveyard to your hand.)

Kami of the Tended Garden

Soulshift 5 (When this creature dies, you may return target Spirit card with mana value 5 or less from your graveyard to your hand.)

Nightsoil Kami

Creature — Human Druid

Soulshift 7 (When this creature dies, you may return target Spirit card with mana value 7 or less from your graveyard to your hand.)

Promised Kannushi

Betrayers of Kamigawa

Flying
Whenever this creature is dealt damage, you gain that much life.
Soulshift 6 (When this creature dies, you may return target Spirit card with mana value 6 or less from your graveyard to your hand.)

Kami of the Honored Dead

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Soulshift 5 (When this creature dies, you may return target Spirit card with mana value 5 or less from your graveyard to your hand.)

Crawling Filth

{B}, Sacrifice this creature: Destroy target nonblack creature.
Soulshift 6 (When this creature dies, you may return target Spirit card with mana value 6 or less from your graveyard to your hand.)

Pus Kami

Trample
Soulshift 8 (When this creature dies, you may return target Spirit card with mana value 8 or less from your graveyard to your hand.)

Body of Jukai

Soulshift 4, soulshift 4 (When this creature dies, you may return up to two target Spirit cards with mana value 4 or less from your graveyard to your hand.)

Forked-Branch Garami

Protection from non-Spirit creatures
Soulshift 4 (When this creature dies, you may return target Spirit card with mana value 4 or less from your graveyard to your hand.)

Harbinger of Spring

Champions of Kamigawa

Flying
Soulshift 4 (When this creature dies, you may return target Spirit card with mana value 4 or less from your graveyard to your hand.)

Hundred-Talon Kami

Flying
Soulshift 3 (When this creature dies, you may return target Spirit card with mana value 3 or less from your graveyard to your hand.)

Gibbering Kami

Legendary Creature — Spirit

Flying
{1}, Sacrifice a Spirit: Target opponent reveals their hand. You choose a card from it. That player discards that card. Activate only as a sorcery.
Soulshift 4 (When this creature dies, you may return target Spirit card with mana value 4 or less from your graveyard to your hand.)

He Who Hungers

Flying
Soulshift 5 (When this creature dies, you may return target Spirit card with mana value 5 or less from your graveyard to your hand.)

Kami of Lunacy

Sacrifice this creature: Target creature gets +2/+2 until end of turn.
Soulshift 3 (When this creature dies, you may return target Spirit card with mana value 3 or less from your graveyard to your hand.)

Burr Grafter

Thousand-legged Kami

Reach (This creature can block creatures with flying.)
Soulshift 4 (When this creature dies, you may return target Spirit card with mana value 4 or less from your graveyard to your hand.)

Venerable Kumo

Menace (This creature can't be blocked except by two or more creatures.)
Soulshift 6 (When this creature dies, you may return target Spirit card with mana value 6 or less from your graveyard to your hand.)