Glad I could help.
You have a unqie concept here, I can't wait to see what you have in store for the quest

Yup, it was great help, as I've had a long break from Oblivion and I didn't roam Cyrodiil's forests for over a year (except for recently playing the excellent Lost Spires).
I've always loved Frazetta's art and it would be very nice to have a quest based on it! Death Dealer is one of my favourite of his paintings, though I never knew there was a comic based on it. I might have to check that out!
EDIT: According to Wikipedia, the comic tells that DD appeared during a war between opposing kingdoms and fought both sides, but disappeared when those kingdoms formed an alliance. Maybe we could tie this into, say, the Cyrodiil/Skyrim conflicts? The Death Dealer would fit pretty well as being a lone Nordic warrior who has fought against Skyrim's barbarian freedom fighters and the Imperial soldiers who oppose them. As a quest, you could have DD send you to kill some Nord vikings invading from Skyrim before they can attack Bruma, but at the same time killing off a party of Bruma guards who are also moving in to fight off the Nords, or something like that. This would be a sort of initiation, though, not the real quest. This would just prove you're worthy of DD's trust to become an ally of his.
For the warhorse, why not see if WhoGuru and Darkrider will let you use a Reclaiming Sancre Tor warhorse? They're the right size and they have the feathers and docked tails. Plus, since apparently Siika is making the meshes for those horses, and he's also making bardings for CHE, he could probably make a barding fit to a warhorse for you.
Also, your helmet has a mask. But in the painting, one of the things I think makes DD look as bad ass as he does is that his face is always in shadow, while the helmet seems to be open-faced. I don't think it would be hard to make those adjustments. I also think the shield should be more yellowish-bronze.
Thank you for the feedback! Here's my take, on points:
1. DD's background: it's not a bad idea - in the Shadows of Mirahan series, DD comes as a balance between the 2 warring kingdoms, then indeed goes away, so this might be a perfect parallel with the Skyrim wars. However, I wouldn't put the DD character onto a certain side - he has to be neutral and a bringer of balance between life and death (ie. too much death brings him around to even the sides). So far my scenario is this: you get the story, find the location (see messages above, about the tree, which is consistent with the Shadows of Mirahan story), then go through a series of tests before the previous DD will pass away and your PC will take over. Note that there is more writting done on this character: back in the late '80s - early '90s there was a series of novels (ie. Prisoner of the Horned Helm, see on Amazon for more), which is talking about the story of an individual who falls under the domination of the above-mentioned horned helm... I will use elements from those novels as well, not only the comics, so the story will be in the end deep and believable. I want to throw DD's background back into the Ayleid wars, and maybe connect it to the ancient mer wars (remember how the Dwemer disappeared and the Dunmer got their colour?

). I have yet more reading&writting to do, but there is a lot to say...
2. DD's appearance: his helmet is a tricky one... In the Morrowind version I used an open-face version only, but I reckon it was looking a bit silly, with the nose poking from under the helm...

For Oblivion, I plan to release 3 versions: open face, lower mask (same texture as the upper part) and lower mask in shadow (easily done since I kept the lower mask as a separate object). This is for multiple reasons: in the original Frazetta DD paintings (6 total), you can see only a shadow; in all the comics and sculptures (including official ones, like http://www.darkhorse.com/Products/Previews/12-679 or -my other favorite- http://media.photobucket.com/image/frazetta%20death%20dealer%20statue/mcknightc/death_dealerIII.jpg, on which the rest of the outfit is based), there is a lower mask or even a full helmet... As for the other meshes, I'm struggling for the lower body piece, will probably resort to a full skirt, since experiments with other robes went so-so until now. Texture-wise, I am quite settled for what I use. I will not go towards a bronze shade, as Death Dealer I is the only painting that shows that hue, although it is not present in statuettes or anything else, but in the original painting - so I assume it is supposed to be just a yellow light falling on the grey metal (just as the horse is supposed to be pitch black, but in DD I it has a brownish appearance).
3. DD's Warhorse: yes, Darkrider already agreed a couple of weeks ago to let me use Mr_Siika's warhorse, after Sancre Tor will be released (and, since I change the original goal of the mod, I believe my mod will be finished well after his). I am also talking master modeller/texturer Waalx into making the harness and saddle for the horse (he already has some extremelly beautiful meshes and textures).
Cheers,
PKR.