Leonard Boyarsky
Leonard Boyarsky is the Lead World Designer for Diablo III, and is the head of lore, dialogues and quests in the game. He is a game designer and graphical artist.
Background
Boyarsky is known for his time with Interplay Entertainment and his work with Fallout 1 and Fallout 2 as well as the time at Troika Games. In 2005 he took a year off for burnout syndrome, and after that was asked to join Blizzard on Diablo 3.
Links
Leonard has a webpage with a gallery of his illustrative work and other information: