I'm pretty sure that Xena has like zero resistance to most esoterics and that it's just PIS/CIS (and sometimes just plain old actual plot) that keeps...
I would argue that her general determination once she started to take her job as a ninja seriously instead of just something to try and get closer to...
I would phrase it more that he instantly killed Trunks after going Super Perfect for the first time because at that point he was done screwing around...