I really like the concept of having some unique weapons hidden around the world and the models all integrate nicely with the vanilla weapons.

But the two weapons I've found so far ("Tempest's Stampede" and "Vigilante's Judgement") both suffer from somehwat poorly written descriptions.
The following is meant as constructive criticism, no offense intended.

Stampede
This only has the minor grammatical error of "it's backstory" (it's = it is) which should simply read "its backstory". A minor nitpick would be the last sentence "This weapon is incredibly heavy, but when you feel it in your hands, you feel unstoppable!"
Try to vary up the language a bit and don't repeat the same word too much, I'd suggest something like:
"This weapon is incredibly heavy, but with its weight in your hands, you feel unstoppable!"

Judgement
The description on this one is just a mess (sorry).
"It was designed by legendary, but Master Smith named Niko and leader of a small but proud clan, but She(...He?) was the last of his(...her?) clan, after it was slaugthered by a rival ninja clan in a single night.
1. "legendary, but Master Smith?" So Niko is a legend, but for other reasons than being a smith? Or is Niko a legendary master smith?
2."She(...He?)" You continue this throughout the text, if you want to leave the gender ambiguous (hinting at it being a Skeleton?) use "They, them and their".
3. You use the words "but" and "clan" 3 times each in a single sentence. Don't.

The other half of the text is mostly fine, besides what I mentioned in my second point. The story is painfully cliché but that's okay.

"A Legendary Mace said to have been designed for shattering the bones of a fully plated warrior. It was created by the legendary master smith 'Niko' who also lead a small, but proud clan.
One day, Niko had been traveling between various clans to garner new allies. Upon their return they found the entire village slaugthered and the mark of a rival clan written in blood.
Niko never uttered another word for the short remainder of their life, instead they fully devoted themselves to crafting this intrument of revenge before setting out to complete one, final task."

I mainly varied up the language a bit more and switched the order of events in the second part. You don't really need to start out by saying that the clan was slaughtered, only to then explain that Niko was out of town and then repeat that everyone was killed.

I'll probably comment on the other weapons when I find them.