Content Update 3.4 is coming this weekend, bringing with it the new Delve challenge league. In this mode, players will descend through the infinite depths of the Azurite Mine while utilizing special light source that will push back against the dangerous darkness.
“The deeper you go, the more dangerous and fierce both the darkness, and the monsters that inhabit it, become,” Grinding Gear said. “How deep can you go?”
In addition to the dungeon crawl, the patch includes several additional skill gems, 26 new unique items, eight divination cards, more light tech, and better water graphics.
Source: Patch notes