Vampire, simply a vampire, if you have Expedition to Ravenloft make it so they have a day heart, if not, add a few more to the CR and make them immune to sunlight damage (or make it "uncomfortable" for them as in daylight sensitivity). They should use bastardswords, as a rule for my group (we use LOTR miniatures all the time) Gandalf and Aragorn have bastard swords, so use bastardswords, as for the Con. damage, the wounding property works great, but it isnt requiured. If you want to be even better say the blade is always poisined with (most likely but not limited too) Dark reaver poison, wyvern posion OR LASTLY Deathblade posion. The wyvern poison is, to me, a good idea since it isnt to hard to resist but can still do ALOT of damage. Now what you need to worry about is the dagger, have it keen (because technically he "crited" frodo) and deliver a disease (dark rider's disease for example) that slowly kills you if you contract it because after all, it needs to be evil. Now the mount could be just a heavy war horse or to step it up a fiendish horse, but even a nightmare or black (or is it dark?) unicorn can do, but whatever you choose needs to be just as deadly as the rider (coming from a player who's goblin had to take on a triceratops riding eldritch giant, its true, the mount shouldnt just run off, nor should it not have the mounted feats to operate ruthlessly and effectivly, make them deadly!) and lastly, have fun with them, the armor is a great idea, but it slows them down when unmounted, nothing is so unterrifying as the monster you can walk away from (that means you zombies!), maybe give it the speed property or make it mithril, also (because nothing pissed the players off more than this), give them some deathroes, nothing makes an evil badguy like fighting desperatly to finish him then having all his cool stuff ripped to pieces.
