I am really into the first paragraphs ideals, portraying Malacath's opinions and using them to smite peoples that do not accept my orc or his "abilities" and i can't really think of a much better way to gain vengence than slaughtering someone just to bring them back and use them to my own ends. Also being a Necromancer does add slightly to being classed as an outcast i would suggest.
I just thought of another possible position. Since there's no Necromantic Lore for the Orismer (As there is with Dagoth Ur, and the Dragon Cults, for examples) this character might actually be the Lich/Warlord in training to "Purify" the world in death. An Outcast to the Orismer, and Malakathi religion, that would make you somewhat of a Meta-Misfit {Necromancer robes, definites} pretty much outdoing even Malakath in His own Aspect! Of course, this would put you at odds with your kinsmen, so you would probably pall around (If you'll pardon the pun) with Dunmer, and Manmeri (Breton) associates due to their greater anscestral experience with Necromancy...
{As a side note in referance to the Necromancer Robes, this is the Misfits' Teeshirt with a logo stolen from an old movie called The Crimson Ghost:}
This wold be the Mission Motivated Megalomaniac, undoubtedly Eeviiil, except if your moral compass has flipped 180 to point South. (Shared pathology with the likes of Hitler, and Manson.) In this case, he would consider Life as Evil, the source of all wrongdoing in the world. Blames Mortality for making people selfish, and competetive, Race Wars, even the Altmer use their Immortality to lord it over the puny inferior mortals.
Unfortunately, He lacks the charisma to conver people the old fashioned way, by convincing them, so he seeks the path of least resistance: Kill them, and make them Obedient, Immortal (Once he gets to Dead Thrall) perfect people. You don't see Draugr fighting amongst each other, right? To them, it doesn't matter if they were Elven, Human, or even Beast in life, now it is one race, to bring the world to perfect Utopia.
So, no Speech, and don't become a Vampire. That's the wrong way, because it's contagious, and dependant on mortal feed stock. A society of Vampires would have to either raid their neighbors, capture, and breed livestock (people, "Make Room Make Room!") or probably both. His ideal would be peaceful, happy (or at least not sad) perfect, and unending. Of course, most people don't understand his Vision, so have to be converted for their own good, as well as the good of Tamriel.
This is how you get Peace by the Sword. You are the Villain, deluding yourself into the Messianic Hero, and opposed by the conservatives out of fear of Change. I'd probably call him a Necromonger.