Dothar Modris is an NPC who is a trade person for Seal of the Protector items. You can also trade 3 Seal of the Elements for a [Seal of the Protector].. He is located in the Market area of Caer-Konig. He offers unrestored Relic Armor, and Ostorian Rings. He also offers the [Wererat Thief] Companion, Enchantment Shards, and items to restore Relic Armor.
For a list of items for sale see Phileas Gram.