A cheap Conspiracy just for your graveyard.
JWolps is likely right regarding the Soulshift keyword considering that Spirits were the biggest tribal type of the Kamigawa Cycle.
It does an even better job with Haakon, Stromgald Scourge though, since it lets you cast creatures from your graveyard to get them directly onto your battlefield, not just on your hand after the right Spiritcreature died as it would be with Soulshift.
What a pity this artifact didn't just cost 
or was made a cantrip regarding the pretty weak actual intention this card had.
Posted By:
Mode
(11/9/2009 10:50:20 AM)
This card + Haakon, Stromgald Scourge + Blood Pet +Bitter Ordeal can cause you to remove all your opponents' libraries from the game by 4th turn at the latest. Put in mana producers like Dark Ritual and you could get it sooner.
Posted By:
shiki10
(7/23/2010 6:49:35 PM)
Obviously to help soulshift.
Posted By:
JWolps
(8/30/2009 12:52:50 PM)
How has nobody mentioned Patriarch's Bidding yet? It's the first one that came to my mind anyway...
Posted By:
Flyheight
(12/16/2010 11:36:45 AM)
Soulless One.
Of course, if you're using Soulless One chances are you're already running only zombies.
Posted By:
Test-Subject_217601
(1/11/2011 12:21:58 PM)
haakon
Posted By:
metalevolence
(11/23/2009 12:43:41 AM)
Clearly meant for Soulshift, but there ARE other uses. Many other uses, in fact. Off the top of my head: Myr Reservoir, Aphetto Dredging.
Posted By:
ClockworkSwordfish
(10/30/2010 10:21:58 PM)
This would probably be broken in block at 1. Even making this a cantrip may be too much in draft/sealed.
Ramosian Revivalist also goes well with this.
Posted By:
A3Kitsune
(3/21/2010 2:15:31 AM)
Thelon of Havenwood
Posted By:
HairlessThoctar
(1/28/2011 5:43:04 AM)
Zombie Apocalypse
Posted By:
pedrodyl
(1/20/2012 5:25:24 PM)