Exclusion Sickness is the umbrella term for the sicknesses which swept across humanity following the Advent war, when a nasty cocktail of Jhoutaioan diseases and Pall Marches gave Earth a trial-by-fire introduction to Curses. They came in many forms, but primarily were the fallout of unchecked Sathiidism spreading amongst wastelanders.
These sicknesses were often the Naissance of Humans of the Era, who were the first humans to have access to the Meta while Aempis otherwise carefull imposed its no-soul edict for Humanity. This gave many Bleakheart a reputation as shamans or witches, depending on how useful they were or how the local culture was biased against them.
Those with Exclusion Sickness and their descendants are today known as the BleakHeart
Exclusion Sickness comes with mutations that reflect the mental state and fixations of the infected. Many of these mutations are also an adaptation to the environment in which the Bleakheart lives, though it may also be a maladaption.
For more information on the possible mutations, or to make your own Bleakheart, please visit the BleakHeart articles.
Poor BleakHeart people. It's one thing when it's a helpful adaptation, but it must suck when it actively makes life harder.
Even when it helps, the status of being a Bleakheart makes life harder in most every Banner, making Bleakhearts one of the hardest to play.