Symbiosis still doesn't work as advertised. At least not with any buff I've tested. Per fiery form it doesn't grant it to close by allies and you. Just some random party member. If that's the goal that's fine but we need that spelled out because it sounds bugged.
Holocaust/exterminate has been using the inferno template since alpha. I held down my attack button for 30 seconds. No warp heat. No additional columns of fiery goodness, no warp damage. I think a pointer thingy is off in the array and its calling the wrong power and always has been. I've never seen more than one column from it since alpha...but I always figured that could just be a graphical bug. Doesn't seem to do damage different than inferno either though.