Pestilence was present when Apocalypse was undergoing the ritual to transfer his consciousness into the body of a mutant with a healing factor when his followers betrayed and buried him. He and the other lieutenants of Apocalypse protected him up until their deaths until the transfer was completed, and despite his efforts, Pestilence was killed when crushed under the weight of the collapsing pyramid. After Apocalypse returned in present day, Pestilence's place as a horseman was taken by Psylocke.
Powers & Weaknesses
Superhuman Strength: Pestilence possessed strength greater than that of any normal human which allowed him to punch through and lift up falling debris to protect Apocalypse.
Strength Limitions: However, he did not possess an equally high level of superhuman durability, which was demonstrated when he was crushed by falling debris.