Maken Shao Andrei
Defeat Andrei in level 1, and do not brainjack Goulnaba in level 2.
Badelaire
Go left on the train tracks in the Lyon level, talk with Badelaire and brainjack him.
Goulnaba
Brainjack Goulnaba in level 2.
Lee Fei Shan
Enter the bazooka room in the Hong Kong level. Go up the stairs to the left and brainjack Lee Fei Shan.
Marguerite
Successfully complete the Vienna level with Rumrod. Use the panel and defeat Marguerite.
Rumrod
Brainjack Rumrod in the sewer area of the Amsterdam level.
Sam Smith
Successfully complete the London level with Badelaire, then brainjack Sam in the tower.
Shaja
Successfully complete the Taj Mahal level with Lee Fei Shan, use her memory to enter Shaja’s room, then defeat him.
Youthfu
Defeat Youthfu in the Mecca level.