Purefoy can find you at the beginning of the game after having escaped the hotel in Pala. If so, he will awaken the player at the Lumber then offer the tutorial mission in the form of your first assignment.
Purefoy is played by actor Jeff Teravainen.
Either after a call from Reuben Oluwagembi, or after the assassination of Oliver Tambossa, he will meet the player at the Marina bar, or at the APR headquarters in Mosate Selao, respectively. Purefoy will then assign the player a mission to kill Nick Greaves and Arturo Quiepo, the other two APR lieutenants. You can complete his mission, allowing him to become the leader of the APR. Alternatively, you can kill only one target - the survivor will ask you to turn the tables on Purefoy. Even if you choose not to kill him, like all other potential faction leaders he is killed at the end of the game at the Jungle Bivouac.