I was interested in Tamurkhan, the character, from early on because he is a Nurgle special character and Nurgle has always seemed poorly represented by special characters. There were none at all in 4th edition and the Fifth edition Champions of Chaos there was only one, Valnir the Reaper, a hero level character who was effectively an undead Marauder. In the latest edition, while each of the other powers got a Lord level character of their own, Nurgle only has the relatively uninspiring Festus the Leach Lord, a low level Sorcerer. In Warhammer 40,000 there is Typhus a spectacular model that always seemed, to me, lacking in personality. With all that in mind, I was keen to see what Forge World came up with.
Tamurkhan is a fantastically (in both senses of the word) horrible concept. A giant, sentient maggot who eats is way into the flesh of a host victim before using its decaying body as a vehicle to drag itself around. In the game this is represented by a decidedly inconvenient rule that allows him to latch on to his killer and potential use him as a new host. This is decidedly nasty and interesting, but essentially from the outside. The concept of being driven around by your killer as your body rots is ghastly and even more so for Tamurkhan's first host, a Slaanesh champion, whose good looks and bejewelled armour slowly decay over time much to Tamurkhan's amusement.
The problem is that all of this horror is from the perspective of the observer. We never get a sense of the personality of motivation of Tamurkhan himself, he remains completely effusive. At heart he is a monster who does monstrous things because he is monstrous. And while there can be some mileage in this kind of nihilistic antagonist the best villains, in my opinion, are those whose motivations you can sympathise with or at least understand. The horribly misguided are much more interesting than the merely horrible.
This is a common problem for Nurgle characters in general and on the surface this is understandable. If given a choice of Chaos Gods to serve why chose the one who makes your intestines rot out of your stomach? It is for that reason that Nurgle followers are often presented as lunatics and death fetishists.
But I think that is a rather tragic misreading of the Chaos God. For a better understanding of Nurgle, we have to turn all the way back to Realms of Chaos: the Lost and the Damned.
"The living know that they will die, and many know that they will live with disease or other torment, yet they drive that knowledge into a corner of their minds and keep it pinioned there with all manner of dreams and activity. Nurgle is the embodiment of that knowledge and of the unconscious response to it of the hidden fear of disease and decay, and of the power of life which that fear generates." (Realms of Chaos: The Lost and the Damned, Rick Priestly and Bryan Ansell, page 12)
This sums up Nurgle's and, by extension, his Champion's motivation. Essentially contradictory, like all Chaos characters, they are individuals who deny or even ignore their hideous appearance in favour of their hugely charismatic minds. Unwilling to face their inevitable decay they simply ignore it. Nurgle is less the Chaos God of decay than the God of human attitude to it, namely denial.
This is how we need to understand Nurgle Champions. Champions of Khorne are blood grazed slaughterers and Slaanesh self-indulgent narcisists, easy. Tzeentch Champions are more complex, but at heart they are weak or ambitious individuals looking to change their fate for the better. Nurgle, Tzeentch's opposite number, is about denying or fighting change. If Tzeentch Champions are the weak wanting to be strong, Nurgle Champions are the strong not wanting to be weak. This need not mean they are struck down with disease. Disease is simply representative of wider decay and collapse which is inevitable in all human activity. Nurgle champions have something, whether it is health, wealth, strength, intelligence or even family, that they desperately want to protect and are unable to do so.
This is why, for me, the most effective Nurgle character was the Death Guard Primarch Mortarion. Faced with a disease even his legendary endurance couldn't resist, he turned to Nurgle in desperation to preserve his and his legions lives, or some semblance of them. In the long run it probably went worse for them than death, but this is the heart of Chaos, entering into a bargain whose long term consequences can only be terrible.
This is why when I invented a background for my randomly generated Nurgle Champion, Rolf Hurtziger, I made him an embittered Mercenary Captain, cast down by Chaos and forced into a pact with Nurgle as no-one else would take him.
As for Tamurkhan, it wouldn't be hard to make him a more interesting and convincing character. At heart he is a physically weak and deformed being who needs to latch onto a host to survive. But each host has a limited duration as it inevitably decays around him. This is never really touched on in the narrative, in fact it says that Tamurkhan held onto the body of the Ogre Tyrant too long and this started to effect his mind. More effective would be to make Tamurkhan desperate needing an endless succession of new hosts in order to survive.
Physically feeble, totally dependent, parasitic and yet charismatic enough to hold together a disparate Chaos Horde, to me this is more interesting that a simple monster.