Have a character under the effects of Fatigue, Poison and Disease at the same time. Fatigue can be achieved from either having a character not rest for long hours or from using the spell "Haste", which triggers the debuff when the spell's effect wears off. The mage spell "Contagion" confers Disease, and the priest spell "Poison" can confer the respective effect, though quicksave when using these spells in case a saving throw blocks them. Don't attempt this in Story Mode, and note that Poison can interrupt spellcasting if self-inflicting the conditions to the character.