The soul mages can be tough in heroic. For a pull with a single soul mage its quite easy, I can take them down way before they do their void thing - flame shock + LvB + CL pretty much kills them.

On pulls with 2, omg...only ran this instance once but i killed one, then wiped, then killed the second one - I guess wiping once on them to continue isn't too bad though, ill try to figure out a better way to do this (hex?) without wiping on a 2 pull though.