From the update:
During the Battle of New al’Jabran, the Deep Crystal’s precarious position out on the city docks, gave way, and the crystal was thought lost to the ocean. Unfortunately for the citizens of the city, an enterprising group of excavators and divers were successful in raising the Crystal back to the surface. When the Crystal broke the surface, a sick purple fog was released from a crack in the magical artifact. Known as “The Miasma”, the fog quickly mutated and corrupted any that came near it. These thralls of the Crystal began to follow it’s silent orders, converting New al’Jabran in a few hours.
To keep the miasma flowing beyond the city the thralls began to grow new crystals, infused with the Miasma, on their bodies. With these they could spread the corruption to others as well as to crystal shards across Halleford. Even crystals of other elements could be corrupted, ensuring that the Miasma could spread its mutation across the world.
In the dark places of the world, sites of worship to Wiggoth, Dark Priests bring back the dead as shambling minions, following the command of the necromancer. Risen Warriors are ancient skeletons capable as fighting as well as they did before their death and instilling fear into the living.
The Unnatural magic that keeps these skeletons together also augments them, allowing them to feed on the pain they inflict upon others. As dark sorcery flows through their marrow, these skeletons are also healed by dark elemental attacks, allowing a dark priest and other evil creatures to support their undead hordes.