Corpsebreath Gas

A chemical weapon developed by The Lacusta Dynasty for use in The Bloodmarch.  It can cause debilitating and potentially deadly chemical burns on contact with a person.  It can easily soak through normal clothing.
The "gas" is actually a mist of very small liquid droplets and not actually a form of gas.  The liquid can contaminate areas for a long time, up to several weeks.  The Lacustans often used special artillery shells to dispurse the weapon in battle.