UPDATE 2 - This has been confirmed to be faked. Source.
UPDATE - This video may actually be a hack instead of a glitch. We're looking into it.
One lucky Reddit user had a glitch pop up after he beat a Lynel. The game froze, so he restarted, and was presented with this glitched weapon. That's the max value for a weapon, and it'll take out anything in one hit. Now if only someone could find out how to replicate this glitch!
Want some proof of how powerful the glitched Savage Lynel Sword is? You can check out it one-shotting the final boss right here.