Despite being incredibly skilled in lightsaber combat and being able to obliterate almost anyone who came up against him, there was one blade which could stop Darth Vader’s rampage or any force users. Cortosis blades were made from highly enriched forms of cortosis metal and were capable of shorting out a lightsaber blade in only a single swing.
These blades posed such a grave threat to Lightsaber users that many refused to even face one. Darth Vader himself was forced to fight one after an Order 66 survivor lured him into her group of fellow survivors by telling the galaxy that Obi-Wan was among them.
Once there, Master Shadday Potkin used a cortosis blade against the dark lord believing she had just defeated him and would soon topple the empire with her fellow survivors. Unfortunately for her Darth Vader doesn’t need a lightsaber to end your life, and instead he quickly choked her to a brutal death…