A couple of friends and myself are looking to run Shadowcleave for the current season and what I want to know is if it's mandatory to run unholy in this comp?

Is the healer protection (unholy frenzy), stun (gnaw), added magic damage mitigation (100% AMS+AMZ), and 8% increase magical damage (ebon plague-bringer) absolutely necessary for this comp to run smoothly? (Not to mention Death's Advance)

Even knowing all the pro's to the spec, I still hate playing it. But, will sacrifice if it is an absolute must.

So, basically what I want to know is if Frost will work with this and how well based on someone's experience with it.
(I know I've seen people play it with frost, but the games seem to be very long compared to the unholy counterparts {could be because it was filo/kollektiv/massivez})

They also wanted to try RetLS, but I'm thinking the lack of slows would just make that comp a major migraine and a half.