In your sword behaviour you have multiple times
do after 0.19 second
kill sword
(surely the same with the spear attack)
The problem is that when you have your collision it kilss your sword, and 0,19 seconds later, it tries to kill your sword again.
Try to desactivate all the kill swords , and see if it works
If it works, try instead of kill word
For every sword on scene
kill sword
If this solution doesn't work, tell us, it will be a tiny little more complicated solution