Really? Why would Harkon want to shut down the sun then?
While vampires can walk in the sun, they are still harmed by it. In Skyrim, their blood boils and they are weaker. In Oblivion, you must feed everyday to be able to walk for 24 hours in the sun without getting burned. Makes sense they want to remove these minor(or major) drawbacks.
Sorry.. as of late bethesda don't realy like to think of reasons why badguy be badguy. There are heaps of flaws to blocking out the sun and i seriously doubt that bethesda would keep the sun out
Wait, what? I hope we see a more grey area with vampires. They hate the sun, I don't blame them for wanting to wipe it out. Same for Dawnguard, they hate vampires, so they go ahead and slaughter vampires. But I bet they might end up like the Silver Hand, self-proclaimed heroes calling themselves the "good guys".