Cast Starring in Terminator Genisys are Arnold Schwarzenegger who plays Guardian (T-800), Jason Clarke as John Connor, Emilia Clarke as Sarah Connor, Jai Courtney as Kyle Reese and J.K. Simmons. Emilia Clarke’s co-star Lena Headey from the hit HBO series Game of Thrones also played Sarah Connor in the TV series Terminator: The Sarah Connor…