A member of the four horsemen, who convinces your character falsely that she is the sole female member of the four horsemen.
You battle her after experiencing a particularly painful flashback and falling down a cliff face. In the flashback, Pestilence says "Ha! The boot in on the other foot now! I knew you couldn't stand against us. And now all that remains is to bid you.....Adieu!"
She is accompanied by Alicia at the foot of the cliff, but decides to face you herself, furious that you hadn't perished along with Littleroot town and its former residents.
After you defeat her, Pestilence and Alicia leave to build a new base. Alicia leaves regretfully, but willingly, nonetheless.
Pestilence only appears once more in the ROM, when Alicia leads you into Meteor falls and betrays you. She appears with Famine and Alicia (now Horseman War), and helps explain to you how they exploited your memory loss.
After you defeat War, the entity of Death appears, and banishes the demons to the Netherworld. She does not appear for the rest of the ROM.