Possessed of an urge to explain away an odd rule

Why don't Possessed have Disgustingly Resilient? I think the answer's fairly simple: GW wanted those units which appear in several codexes to be as homogenized as possible, to avoid confusion or whatever. But narratively, it's a bit tricky. Nurgle Daemons and Plague Marines both have the rule, so why would a fusion of the two not have it...

... unless they aren't actually Plague Marines. What if they're actually loyalists who have been possessed against their will? Subsequently, the spirit of the loyalist and the daemon are constantly battling for control of the body - not a goo recipe for Disgustingly Resilient.

I figured that it would also add a nice splash of colour to my army.

I decided that the appearance should representa violent internal conflict, with some limbs transforming into Plague Marine limbs whilst others mutate out of control and other areas are defiantly Imperial. I used bits from loyalist Space Marines, Gors, Plaguebearers and Plague Marines to achieve this. The Son of Medusa's long, ripping guts were created by sawing the body in half, creating a long central section with a long pin and then building up flesh from green stuff.

These are just the first two. I have an image of one doing a horrid crabwalk and a Terminator who looks like he's had a run-in with John Carpenter. We shall see!