Well, having watched a lot of Youtube videos I tried to fix the waist and arm of the dud NecroConda. Waist was fine, but the elbow didn't work right after the joint swap either, I think the actual forearm itself is defective. I can anchor it in place and make it look right but it won't bend without coming apart. Ah, well.
This does make me very iffy, as noted earlier, on getting any more. Two out of two identical figures had issues, built one good one and made one somewhat better with parts from an Ollie's MOTU mold Wrestler I got cheap. Not how I want to spend money or time, honestly. I'm wondering about the Thundercats/Grayskull Mumm-Ra and Lion-O now, do I want to plan QC roulette?