Hi, what i've found to work best for me is following:
1. SB:SoC - Main Target
2. SB:Haunt - Main Target
3. Agony - Main Target
4. UA - Main Target
5. Spam SoC - Main Target
Its pretty much the same priority as if you were on a single target bossfight, however, instead of using drain soul as a filler, youre using Seed of Corruption. When you have all 3 dots on your main target, SoC will trigger instantly, so at least with my 10% haste atm, i can just spam it and it will trigger while im casting the next one.
Also,
does the first SoC explode when I reapply it to the same target?
- You'll still be dealing mediocre damage at best. I'd say Im doing around 15-17K dps on 5-6 mobs with this method at ilvl 634. So its still far behind what other classes can pull.
For 4 targets: Keep all 3 dots applied to all targets + keeping up SB:Haunt. You wont be having much time, if any at all, to use Drain Soul in this situation. Its more important to keep dots up on all targets.
For 3-2 targets: Pretty much the same as with 4, however now theres a little time for some Drain Soul channels here and there.
I hope this information helps. I used to apply UA and Corruption to as many targets i could when there was alot of mobs too - but with the state of most other classes' AoE, shit's dying too fast and its really just pointless. SoC SPAM all the way!