Crown of the Lich King
This ornate circlet radiates evil and necromantic magics; whosoever wears it is able to treat any necromantic magics* as one level lower when communing or preparing spells, and takes +1 ongoing to cast such spells. Finally, such spells are Empowered (as the Cleric move) if appropriate.
The crown, however, brooks no impostors from the living. If the caster achieves a partial success on casting such a spell, he gains a physical debility of the GM’s choice as the crown drains his life energies.
Should the caster ever fail a roll to cast such a spell, or if he achieves a partial success while having all three physical debilities, then the crown snuffs out his life. If the wearer, then, fails their Last Breath roll, their body rises again as a vessel for the Lich King himself to inhabit.
*GM interpretation, but speak with dead, animate dead, trap soul, consume unlife, contacts spirits, cloudkill and soul gem come to mind.