I do assume you watched the heroic video from UP?

If not you can watch mine i run nearly the same setup only i use a ele shaman instead of a BM hunter-> http://www.wegame.com/watch/Up_heroic_multiboxed/

Like already mentioned DK shine on this encounter thanks to death grip,strangulate ++ all the cc he can use on the casters.

The harpooners net you and run away wich is annoying + the meele's hamstrings you. Use your tools (hand of freedom and 2x masters call.
Shadow res aura counters the shadow casters okey but not nearly enough.

ALWAYS kill the shadow casters first, thoose shadow bolts hits hard and fast. The harpooners dont hurt nearly on the same level.

When Skadi lands i ususaly pop divine protection to make the transiton less stressful.