A power to summon him can be obtained as a reward for completing the Black Book quest Untold Legends.
He can only be summoned using the Black Market power. When activated, he appears and offers to trade much like a regular merchant would. He will buy any type of item, except stolen items, and he sells armor and weapons based on the Dragonborn's level at that moment. At higher levels, he is the only merchant in the game who will sell both Dragon and Daedric armor and weapons.
He has 2,000 available for trading, which resets after two days. He is not affected by the Master Trader perk, nor can his business be invested in. He will also refuse to buy stolen items, unless you have the Fence perk in the Speech skill tree.
- Ah, a fresh mortal to bargain with.
- Ah, sweet Oblivion. Soon I shall return.
- I do so love dealing with mortals.
- Until you summon me again.
- So, we meet again.
- So soon? You must be hungry for a deal.
- You have many things I wish to buy.
- I'm sure we can strike a bargain.
- Haggling with you can be so...entertaining.
- Let's make a deal.
- I can hardly wait.
- The Merchant will refuse to do business if summoned while trespassing. When activated, The Merchant will respond "You're not supposed to be here." and won't offer any dialogue options. Leaving the trespassed area will allow bartering again, but his gold will be set to 0. After approximately 2 in-game days his gold will replenish.
- The Merchant sells Daedric and Ebony equipment before many other merchants do.
- Due to the "Invulnerable" tag enemies will never target the Merchant. In this regard he has same stats as Dremora Butler. 
This section contains bugs related to Dremora Merchant. Before adding a bug to this list, consider the following:
- Sometimes when trying to sell anything to him, the item will be removed from the inventory, but he will not give you any gold in return. Waiting for him to disappear and then summoning him again does not appear to fix this either.
- Sometimes when summoning him, he will have no items and 0 gold. To fix this simply wait for him to despawn and wait a few seconds, then summon him again. (This is caused by summoning him, selling off your loot, waiting 48 hours for him to respawn his gold, and trying to summon him again. Most likely occurring when deep in a dungeon and not wanting to leave, but having a lot of loot to unload. To fix, simply walk a few steps, wait an hour, and re-summon).
- If playing on a newly loaded game, he will have the default random sales and have 2,000 gold. If you load another save, he will resume whatever inventory and gold amount he had in the previous save.confirmation needed
- loading screens are also black. To fix, save and restart the console. Sometimes when selling, your items will turn black, even after you stop selling to him. Items on
additem fcommand appears to have no effect in raising the merchant's gold above 2,000.confirmation needed Using the