This is a remix of “Katana for Dummy 13" kh4rj0
Based on DUMMY 13 Beta - Oct. 2023
Get your original Dummy 13 here: “DUMMY 13 Printable Jointed Figure (BETA FILES)” by soozafone
You will find more of such stuff in my collections:
https://makerworld.com/en/u/2185604356/collections
The holster is simply inserted into the hole on the back of the DUMMY13.
Have fun.