Diablo/Gharbad, the Weak

You will find this quest at the level 4 dungeons.

Gharbad is a Clan unique demon that will not attack you. Instead, he will beg you not to kill him in return for a magic item. Do the following:
 * Leave Gharbad and go find some minions to kill; you may need to travel to a new floor and fight there.
 * After some time, head back to Gharbad and he'll tell you he needs more time to finish making your magic item.
 * Go back to fighting minions, but return once in a while.
 * After a certain amount of time Gharbad's response will change; he will now say that the magical item he made is too strong for you. Gharbad will then betray you and try to kill you. Simply destroy him. Upon slaying Gharbad, your hero will say, "I am not impressed..."