I really dig the Venthyr theme and rewards so I went for that. While leveling, I also found that the Venthyr ability was much more useful than the Necrolord one. Less damage but lower CD and the RP makes it versatile for spamming Death Coil/Epidemic or Death Strike. It’s also loads better for Blood. Abomination Limb looks way cooler though.
I really liked using Shackle the Unworthy but I found it just wasn’t as useful as Swarming Mist.