Twistedphish

I'm on a reread of Wax and Wayne, and in bands of mourning it is mentioned that kandra spikes can't be transferred between kandra as it causes a lot of pain, but in era 1 TenSoon kills OreSeur and uses his spikes, swapping out with his own at will. Why is he able to do this? The only thing I can think of is since OreSeur "dies" the spikes are no longer attuned to him, but I'm not sure that's really how that works.