I recently faced another player, Gephicka, in an Open tournament (played one round a week) and the team I built was my take on Hard Trick Room in Regulation H UU.
The team consisted of:
Gardevoir
Gardevoir is the first Trick Room setter. It carries Dazzling Gleam, Psychic, Encore, and Trick Room. I'm using a Covert Cloak set with Tera Fire, invested heavily in physical bulk. However, it still carries a Modest nature, and is able to dish out good spread damage with Decorate boosted Dazzling Gleam. Encore is used to lock down endgames, as it prevents opponents from Protect stalling in front of a partner like Conkeldurr.
Gallade
Gallade is the second Trick Room setter. It carries Psycho Cut, Sacred Sword, Protect, and Trick Room. It uses a Clear Amulet with Tera Grass, and is invested fully in HP and Attack. Decorate boosted Sacred Sword and Psycho Cut are able to annihilate most of the meta. However, Gallade is frailer and isn't able to dodge Fake Out, so it's more of a risk to lead it in some matchups. Regardless, it's an effective setter and sweeper.
Chandelure
Chandelure is the third Trick Room setter, and is intended to be a special nuke. It's holding a Life Orb and invested fully in Special Attack, allowing it to deal massive spread damage with Heat Wave, and cover most teams with its 3 attacks. It becomes unstoppable if it receives a Decorate boost as well. The main issue is that unlike Gallade, it doesn't have Protect, nor does it have another defensive option like Encore, so it's a far more "all-in" Trick Room user.
Conkeldurr
Conkeldurr is a Trick Room attacker that uses Guts to sweep with its unresisted coverage of Close Combat, Knock Off, and Facade. It's trained to be faster than minimum speed Smeargle to gain momentum from Decorate. It's honestly the worst thing on the team in testing, but it's still a great sweeper that puts up shocking numbers, as it has the same Attack stat as Ursaluna. Wish it was bulkier, though.
Smeargle
I don't like Smeargle. But I kind of had to use it for the strategy to work. Decorate, Follow Me, Fake Out, and Spiky Shield work in tandem to allow Trick Room to go up consistently, and make the team stronger. I don't like Spore Smeargle, it's mean. In seriousness though, I deliberated on whether to use Spore or Fake Out, and opted for Fake Out. I feel like all 4 of the moves I chose are mandatory on my team, and so I dropped Spore. Given Fake Out
proved to be useful against Gephicka, I think I made the right choice, though I am seriously considering which moves I could drop for Spore. Tera Grass is used to block opposing Spore, and it's obviously holding a Focus Sash.
Murkrow
Last but not least, Murkrow. I needed this to be a swiss army knife to deter whatever Gephicka may bring. Given that, in this very thread, they made a post praising Basculegion-F, I was certain they'd be bringing it. Coupled with my Chandelure's Fire type, I decided to use Murkrow a sun setter that also has a lot of general support options. I opted for a moveset of Foul Play, Haze, Taunt, and Sunny Day. Tailwind is unnecessary on this team, of course. Additionally, Sunny Day + Foul Play allowed me to win
game 2 and the set.
Also, there was a Reg I tournament earlier in the day, which I won. I don't feel like writing a long analysis, so here's the winning team:
