So, I have an old, experienced character who is a vampire, and lately it's been bugging me that, apparently, some time ago I wasn't thinking and took on Meridia's quest to clear her temple. I have no idea what compelled me to do it, except maybe at the time I was attempting to get the Oblivion Walker Achievement.

So now I realize Meridia is abhorrant to all forms of necromancy and undead. My Altmer was a vampire at the time, is there any reason she would allow a vampire - an undead person - to cleanse her temple? I'm quite attached to this character, so I hate to abandon him. Is there some way to justify this having happened?

Edit: Oh hell no, the quest is called "Break of Dawn," I am so sorry.. If a mod would change the abomination of a title, I would be most pleased..

I'm so sorry

Mhmmm ... to my mind the first thing that came is...
That the programmers did not take account of that
On the other hand... if you want to justify it ... well.. perhaps that daedra does not care of it, as you are just a tool, and as long as you cleanse the undead with the blade, is ok, ...
Like Blade... a vampire that kills vampires.

For the sake of letting the undead kill each other?

because she is not programmed to care

because the devs cant account for everything

Because it would take too much time to program her caring.

Because on long road it may end up in more undead getting slain by her light.
Also, making friends wit ha Dragonborn is always a worthy gamble. Daedra LOVE dragon souls.

She wouldn't. The makers of the game just didn't think about that.

Yes they did. It would just take too much time to code it.