There are 3 major factions in this campaign, with minor appearances by other races.
Chaos
Lead by Chaos
Lord Dreagher, the Exalted Champion of the Khorne Daemonkin (played by Marc Chong)
His lieutenant Lord Gallowbraid,
the self appointed leader of the Stygian Claws (played by Somjai)
Lord Demanex the Tormentor, a follower of Slannesh (played by Darryl Chan)
Imperials
Lead by Lord Commander Augustus, of the Cadian 665th, assigned to Ichron III (played by Abdullah)
Captain
Aerius Gaius, Shadowlords, Ravenwing Successor (played by Aaron Wong)
Chapter Master Jerith Hyrcanus, Grand Master of the Exorcists (played by Bernard Low)
Necrons
Nemesor Demekor the Insufferable (played by Jun Yi)
Nemesor Simutekh, The Blood Phaeron, the sleeping Necrons (played by Nick Ng)
Minor Characters
Canoness Mirane
Brother Captain Lieto of the Grey Knights