I just got this Super Rare Item from Treasure Hunter on June 31, but I have no clue what it does.  Is it a magic combat weapon (it's wieldable and increases Accuracy...) or does it do something else?  I've looked around and the only information I can find about it is when it was put into the game and it was some kind of promo item that shouldn't even be available anymore, as the promo supposedly ended in May.

So what's the deal?  Does it actually do anything or is it just a Dwarven-styled Wand/Staff for combat magic?

It's a dwarven style wand - part of a promotional set of imcando styled weapons.

 

It's pretty common place for sites to suggest/imply items are no longer available after their promo ends, but in reality the vast majority that are TH only content remain on there as super rares they are just so rare it takes ages for people to actually confirm they are still there.

It more or less functions as a tier whatever-you-convert-it-into duel wield magic weapon. With Evolution of Combat most weapons of the same level are close to identical. So it more or less is just the same thing with different cosmetics, as Sy says.

 

They are still on TH though (and in the Rare Item Store I believe, but that's another story) for whatever reason. I see those items flicking through potential prizes all the time.

Okie doke, thanks for the quick answers.