The Runewright is an Ofieri craftsman in The Witcher 3: Wild Hunt added by the Hearts of Stone expansion. He and Dulla kh'Amanni sell goods to locals at Upper Mill, where they are stationed as part of an Ofieri delegation. The Runewright may also use his arcane knowledge to considerably improve Geralt's equipment.
He describes profession of runewright as being part smith and part mage. There are three "tiers" of being runewright - amateur, journeyman and master. Worthy note is also fact that this art is very expensive. Amateur level enchanting costs 5,000, journeyman costs 10,000 and master level costs 15,000.
Associated quests Edit
If you have the necessary runes for enchanting, he does it for free (checked with patch 1.31).