Trick room setters:
I personally favor Pokemon like Hatterene and Glowking (Galarian Slowking) in Ubers even though they're not Uber level Pokemon.
Let me explain. Hatterene is a very versatile Pokemon. It can fit a teams needs by whatever it does, whether the team needs another trick room abuser (easily done by its ludicrous 136 base spatk), or be offensive support (access to moves like nuzzle and healing wish). It even can function as a sweeper with calm mind.
Glowking on the other hand is a great choice, due to having regenerator and access to Chilly Reception, which allows the user to takes hits for their mons, then swap out. Glowking is renown for its consistency, which allows it to continuously set TR and wall mons for the team.
In the end, I still like Magearna more than these Pokemon.
Trick Room abusers:
As you have mentioned, Calyrex Ice, just Calyrex Ice, I cannot say anything more, Calyrex Ice is the literal only thing you need. If you need secondary TR abusers, I would recommend Ursaluna, Enamorus-Therian, and H-Braviary.
Ursaluna is just sheer damage with guts façade, Enamorus-T is great due to great coverage with earth power and moonblast, and H-Braviary also hits monstrously hard with specs tinted lens hurricane/psychic. These days, I've also seen some people running Banded Rayquaza on TR teams, but I wouldn't do that.
That's all I have to share, overall, I don't recommend playing TR in ubers. It's way too risky with high pressure Pokemon like Flutter Mane, Miraidon, and Palafin, who can instantly kill you before you even set it. I personally would play TR in ou, as there is a lot more choices there.
