Black Glasses in Pokemon Sword and Shield will give a boost to any dark type moves the Pokemon holding it has. In Isle of Armor especially, this can be useful for your Kubfu if he was evolved to Urshifu through the Tower of Darkness. Since Urshifu acquired through this tower are fighting and dark types, this is one useful location for the glasses. However, they will be useful with any Pokemon who has dark type moves. Here is where you can find them in the Isle of Armor.
How to get Black Glasses in Pokemon Sword and Shield’s Isle of Armor
The pair of Black Glasses will be sitting on the ground in the wild area. From the Soothing Wetlands, the area where Mustard’s Dojo is, head east to Brawlers’ Cave. There will be plenty of items and Pokemon for you to grab in here, but for the glasses you will need to go up all of the slopes in the middle of the cave until you come out onto Challenge Road. At the top of the slopes and staircase here will be the before mentioned Tower of Darkness. Simply walk around the back and there will be two items on the ground (as well as a dynamax raid den). The red one on the left is the Black Glasses you are looking for, while the yellow one on the right will be a TM.
Now that you have the glasses, be sure to give them to a Pokemon that knows at least one dark move, otherwise they will not be doing anything for you. Just a sample of dark type moves include Payback, Bite, Crunch, and Sucker Punch. Enjoy your boost in power and be sure to keep checking back with Gamepur for more Pokemon guides.