Poisoned Character Roguelike

You have been poisoned, or stabbed with a wraith-blade, or what-have-you; and you are slowly becoming ill, insane, or turning into a wraith or some other horrible being. (Maybe your body is being transformed into the servant of an evil being against your will.) In order to avoid a horrible fate, you need to travel across a great wilderness or delve into a deep dungeon to find the only cure (a potion, a herb, a healer, etc.), and time is running out...

"Slowly" is completely open to interpretation—your prognosis might an hour, a day, a week, a month, a year, or an even-longer time period.