I guess I got what error you are having...
I tried to fix it, but I fail... frown
As your knowledge is better than mine, may be you should try set trail position to swords position, in while loop? Cause it looks as trail is not set to swords position.

Looking for free stuff?? Take a look here: http://badcom.at.ua
Support me on: https://boosty.to/3rung