Seal of the Exorcist

Seal of the Exorcist is an epic caster ring that boosts stamina, spell power, and resilience.

Source
This item is sold by special vendors that take Spirit Shards. Players can use the Shards to buy items from:
 * Spirit Sage Zran in the Allerian Stronghold
 * Spirit Sage Gartok in Stonebreaker Hold

It costs to buy this item.