Half a year ago, I wrote down a small wish list for gen 8. What I wanted was for Bug finally having access to Trick Room since I like Monotype and VGC, and having a little bit more variety never hurts. I theorized that for my wish to happen, we probably need a Bug/Ghost or Bug/Psychic Pkm. Looks like my wish finally came true in the form of Orbeetle.
I must admit I wasn't really impressed by its stats as it faced tough competition from some Quiver Dance user like Frosmoth. Though, design wise, it does look intriguing in my eyes.
Anyway, when I looked at Orbeetle's stats again, I realized that not only could it have access to Trick Room, it's also probably bulky enough to pull it off in a double battle, especially one geared towards monotype. If it gets some nice support moves like Follow Me--it certainly looks like as if it could pull it off--I'm certainly sold on it. It even has solid partners in Vikavolt, Escavalier, and Araquanid, the latter being able to protect you from Rock Slide and Heat Wave through Wide Guard. If you fear a fast and strong fire, dark, or flying Pkm, well, there's Accelgor's Final Gambit to deal with that. It also allows you to safely send out one of your slow Pkm when Trick Room is active.
If Orbeetle gets Psychic Terrain, that's even better because aside from a self-imposed monotype double battle, many players would want to have it on their team to prevent Fake Out in VGC in general. If that's not enough for you, you have some strong Psychic Pkm in Reuniclus, Gigamax Hatterene, Gardevoir, and, maybe, even Mr.Rime, all of them being slow or somewhat slow.
On another note, I might sound like a broken record, but I'm still not over Coalossal. I really like the basic Pkm, but aside from Coalossal's bulk, I'm not really sold on its attack stats, unless it gets Huge Power (though, that might be too much) or, what is more probable between the two, Sheer Force. Nidoking is a nice wallbreaker although its SpA isn't very high. While Coalossal might not have Nidoking's insane movepool, with its stats, something like Heatwave, Earthpower, or Rock Slide should suffice for VGC. Resisting fairy is always nice, and with the right support, water and ground moves from opposing Pkm shouldn't be much of a problem.