Been leveling my necro with this build (using FC instead of SM) and as promised up-thread I share my experience.
It.. is... holy-christ-on-a-bike-gawdwaful
Now, before you rip me a new one, let me explain the context..
I am fairly new here so I just pug around in threatening (and a few runs perilious when I find a team and have a character I feel comfortable playing). Life in threatening pugs is pretty much a run-and-gun game where no one will tank anything and barriers are a rare commodity. In this context what this build does is:
1) Spread a lame DOT with walking bomb that will cause enemies to attack me.
2) Spread another lame DOT with virulence + FF that will cause enemies to attack me
3) Has simulacrum which prevent me from HoK ressing and makes sure no team mate will ever ress me (they have ran off by then...)
Now, mostly this problem seems inherent to walking bomb (and the terrible curse that is simulacrum that you have to take to get to it...) but with the ice mine build I could at least drop IM on myself and be reasonably tanky against all the aggro I get. FC is nowhere near enough to keep me alive and I cannot even imagine what it would be like playing without any defensive cooldown.