Dawnguard

Short idea.

Reborn in Skyrim, create your own character.

You appear in fort dawnguard with the deed to the fortress. You have a system that lets you repair and upgrade the fortress and valley.

The system also lets you summon troops to help you fight the vampires, how you want this to be is up to you, whether the troops are all generic dawnguard hunter or if the start as farmers and upgrade using a system similar to mount and blade.

Have fun with it, maybe you will eventually make peace with the vampires in Skyrim by marrying a vampire princess (wink wink serana) and the focus on the vampires around the world, when that's done maybe you achievements elevate you into a new aedra or deadra god.

When you become the new god you could get powers to go to any dimension that has vampires for you to hunt, like twilight or highschool Dxd etc have fun.