I've been having second thoughts about using the marines exemplar for my chaos/good guy/inbetween space marine army, so I've had a new thought...
The Hellhounds will be a chapter in their own right, whose chapter master fell into darkness and was exposed as a chaos-worshipper, yet died saving the imperium from a gigantic tyranid/tau/ork/chaos/necron incursion by luring the enemy horde onto the hellhounds chapter planet and then destroying the numberless hordes, along with said chapter planet (a suitably heroic fashion just this side of draigo....) and with him gone, three powers split the chapter. The pro-imperials, who saw their masters death as sign that they should redeem the hellhounds name and strive to save the imperium. The chaos worshippers, who fell with the chapter master but did not want redemption, and the 'grey' section of renegades, who would wish to remain part of the imperium but feel aggrieved by it, just as their master did, and now cannot see how the imperium would ever welcome them back.
The chapter planet may have been called Quinaros, the fifth planet of a system, or the chapter may have been descended from the white scars, nobody knows but many display the roman numeral V, or the inscription 'Legio V' upon their armour....
Also, I'll be keeping the exemplar colour scheme on the whole, with a few changes and quite a lot of individualisation. Maybe something like this:
Or, like this (but with fangs painted around the mouth grill on the black bit):
Or, I may come up with something different. I'm currently undecided, so If any of you have any thoughts I'd be glad to hear them!
That's all for now peeps,
Adios!