Sounds cool! do you think the new patch will affect this? And what exactly is rot?I would say it like this
Blood - Known mainly for it's healing ability, however at 101, a couple of leech pieces can make this entire spec obselete
Unholy - Good for spreading dots, would be amazing for farming
Frost - Nice base aoe spells, no need to rot, base high damage
So choose whichever you prefer between frost and unholy, skip out on blood.