[Name] Ravenloft Viruses [Source] Ravenloft Monstrous Compendium Appendix III: Creatures of Darkness [Symptoms] 
Theses six incredibly lethal magical diseases were created by an evil wizard who was killed by his six sons, who each became the first carrier of one of them: Combustion (the victim experiences a horrible fever and eventually bursts into flames), Crystal (the victim's blood starts to crystallize from within), Petrification (the victim gradually turns to stone) Phobia (the victim becomes terrified of everything), Psionic (the victim rapidly gains intelligence and psionic powers until his head explodes) and Shadow (the victim eventually fades into darkness). Each disease is very contagious, especially from the remains of a dead victim.