Mario & Sonic Guy
Old rivalries live on!
I guess when I think about Trick Room users, Bronzong, Dusclops, and Reuniclus would come to mind almost immediately, but I've seen at least one Mismagius with Trick Room, so that's something that could catch you off guard.80 base speed is a middle road in terms of speed; There are other 80 base speed Pokemon such as Chandelure (Who also can use Trick Room) and Dragonite who can use Trick Room and a negative nature to beat a lot of things under Trick Room. Chandelure and Gallade are also ideal to negate trick room because they are in that speed that can be fast enough to beat a lot of things without trick room but can also be slow enough to take advantage of it themselves.
I was going to mention Bronzong, but I was beaten to it; You could also try Malamar and Gourgeist if you're willing to find a Super-sized Pumpkaboo.
Uxie could also work as a Trick Room user AND a Trick Room counter, thanks to its access to Imprison, and it has the defenses to act as a supporting wall. I even got the idea of treating Uxie as a Trick Room counter from a random Wi-Fi battle; my Trick Room team once got shut down when I went up against a Chandelure who knew Trick Room and Imprison.