Arnskar Ember-Master is a blacksmith who appears in The Ragged Flagon after completing the third of the special jobs Delvin Mallory gives you. He is a merchant, selling Weapons , Armor and Smithing supplies. His shop is in an alcove on the north wall. It contains a forge, grindstone and workbench.
Weapons, apparel, and misc: Arnskar's inventory is pretty standard of that of a blacksmith. That being said, there is still a good selection in quality and quantity no matter what you might want to smith.
"Looking for the best smith in Skyrim? You found it."
"Need your weapon repaired? Or can I interest you in a new one?"
"They don't call me the Ember-Master for nothing. What do you need?"
- The Elder Scrolls V: Skyrim (First appearance)