You can all go to hell. I mean it most sincerely.
Finally got my hands back on the cremator (after noticing that if a cremator is present on a map and did shoot at least once, the MP7 and the OICW will fire with the flamethrower particle effect. Weird, but fixed already. So where was I?), fixed its effects and some behavior aspects.
As you can see, this is a footage of a cremator fighting some zombies on a test map. It may be not apparent, but some of the cremator's features are: a) zombies are priority targets. If a cremator fights an enemy and notices a zombie, it will switch to killing it in a first place. b) ignites enemies. _Should_ ignite zombies and did so earlier, but now for reasons currently unknown zombies just turn black and don't burn. Headcrabs do. c) is, by itself, tolerant to flame. d) (not shown) drops head post mortem if killed with an explosion or by a shotgun fire.
Bugs: a) has some problems fighting moving targets (shown). b) ambient sound can continue after death (a common bug for many HL2 NPCs). c) shoots for a second time after dealing with a lone common zombie.
Todo: a) make enemies' bodies dissolve. b) post-mortem Immolator fuel drop. c) melee attack. d) dynamic lighting effects. e) make a cremator throw a gas bomb (abdomen sphere) at the player character when close to death.
Oh, and the video is recorded with FastStone Caprure.