Death Knight and Holy MonkFollow

In order to help my friend level up to 80 on his holy priest, I thought I'd take the chance to try a Death Knight and level with him through outland and Northrend. He's almost 58 now and specced fully holy. I was wondering which build would fully ultilise the help of a holy priest?

I'm guessing causing the most threat and having aoe abilities would be a given. I'm tied between the frost/unholy trees as they have some nice treat and disease abilities.
I didn't think the blood tree would serve me much use, and I wouldn't need the ehal from blood presence and any of the healing abilities from the tree.

I would probably go with unholy. You will be able to pull a ton of mobs and aoe them all with the priest healing you. I specced unholy and can do quite well aoe'ing without a priest. So I imagine you can do quite well. Here is my character and spec http://www.wowarmory.com/character-sheet.xml?r=Spinebreaker&n=Shwayzo Hope that helps

folsomdog

Unholy. I used my 70 priest to help my boyfriend's Unholy DK complete some group quests. Just for fun I overhealed like crazy, and dps'd. We also tried AOE farming Nagrand birds. I think I only pulled aggro from him once.