My Renegades

General Baites came up with the back story for his Imperial Guard army a while back, and I hopped onto it when I started getting into my Renegades.
The gist of it is, on Hastia III (the planet under observation from my Iron Host), there was a rebellion of sorts and the planet ended up in turmoil and the higher ups were following Chaos. Somehow all imperial distress calls were denied, and the planet went unnoticed. So while most of the planet is dedicated to Khorne, there are some followers for the other gods.
Upon making contact with the Iron Host, the leaders struck a deal: any worshippers of Nurgle on Hastia III may be shipped to the Iron Host's planet and attached to them. Along with the Nurglites, cowards and the like were thrown in as well, an effective way to get rid of the weak. In exchange for taking care if the human trash and whatever research available to the Devourer Plague, Anthrallis and his men were given access to the 3rd planet's forgeworld moon, for tanks, guns, and armor.
The Nurgle worshippers brought to Hastia V, Newly renamed 'Poxvidrae' by it's inhabitants, were given halfway-decent armor (read 6+ if they were lucky) and advanced respirator masks, the better to serve as the willing chaff, meatshields, and artillery operators for the Host.
The others, were not so fortunate. They were exposed to the planet's atmosphere without any form of protection and became trees in the grand forest, or were experimented on by the warpsmiths.

From a modeling standpoint, I used cadian bodies and, to represent the rebreathers of the mortals serving the  Iron Host, I had to look around the interwebs to find something that would make the models all uniform. I didn't want any exposed faces, even the higher ranking ones. After scouring, i came across Pig Iron Productions in the U.K. and they had the perfect ones (see below).
They even have slits in the face shield that look almost like the insignia of the Iron Warriors. And they're even big enough that I could try my hand at some free hand to add some uniqueness to my dudes.
Pig Iron has a ton of alternative heads to choose from all for pretty cheap.
I haven't gotten the chance to actually order the parts, but I am anxious to get them.
I hope you find something on their site to spruce up your own collection!