Lokhtos was the overseer of the Thorium Brotherhood during the War of the Three Hammers and the Dark Irons' enslavement in Blackrock Depths. When the rest of the guild escaped, the aging Lokhtos chose to stay behind, believing he would only slow his compatriots. Despite his abdication, Lokhtos remains a respected member of the Brotherhood, though he keeps his allegiance to himself to avoid reprisal from Ragnaros and his elemental minions. When not at work in the forges, Lokhtos is often at the Grim Guzzler; from a darkened corner he quietly conducts business on the guild’s behalf. Lokhtos’s opinion of a person has a definite effect on how the rest of the guild views the person.DF 161
When you reach reputation becomes friendly with the Thorium Brotherhood, Darkbargainer will start selling plans and pattern available to friends of the Brotherhood. As your reputation goes higher, you will gain access to more plans.
The conversation between the player and Lokhtos Darkbargainer if a Sulfuron Ingot exist in the player's inventory:
A Sulfuron ingot?!??! Impossible! I must have it! I must! I must!
<Race>, I am authorized to make you a grand deal for that ingot. Perhaps you would be interested to know the secrets of the Hand of Ragnaros? Sulfuras, idiot! The legendary hammer of the Firelord.
Hrm, I'm listening. What is this offer?
In exchange for one Sulfuron Ingot, I am authorized to grant you one copy of the plans to forge a Sulfuron hammer.
Now an adventurer like yourself is probably thinking to <himself/herself>, "What would I ever need a hammer like that for when what I already own is far superior?"
Well let me tell you something, <mister/missy>, there ain't nothing more superior than what the Sulfuron hammer can become!
You've got my attention.
You see, all you gotta do is forge the Sulfuron hammer and find yourself the Eye of Sulfuras. Combine the Eye of Sulfuras with the Sulfuron hammer and it will become Sulfuras! Now I'm not going to bog you down with any technical information as to where or how or when you can get an Eye of Sulfuras. I'm sure you'll figure that stuff out. Just sign this here contract so that our agreement is binding and our business will be done.
Give me the contract.
Lokhtos Darkbargainer begins casting a powerful spell. A green shield of magic surrounds him for a moment, and the entire bar shakes. [Thorium Brotherhood Contract] appears in the player's inventory, and Lokhtos points at him/her.