Uhh, I'm guessing your playing NatDex cause if your opponent is using Mega Sableye in SV, I think you should be worrying more about that then a stallbreaker.
A mon that I have found good against stall is magic guard reuniclus with calm mind, recover, psyshock and energy ball. It eats up most hits and doesn't worry about passive damage. It does horribly against arch teams, but if your not worried about that, then it could be good, though it does seem like you've got it covered.
Potentially a focus sash polteageist could be good, as at +4, which you can get easily from shell smash and weak armour, can outspeed barra in rain. You do need hazard removal, on the psychic terrain team I've used it was tusk because that can help against dark types so you can spam expanding force easier.
No, those games were custom. Most of the mons from that custom team were mons that could at least be found in gen 9 OU like Blissey, Heatran, and Alomomola. But I haven't seen a Wo Chen or a Toxepex in OU for awhile. Regardless, the rest of the games were all gen 9 OU. I only mentioned these ones due to the lack of real stall games I have been seeing with this team.
It's less about being good against stall specifically. It's about if mixed attacking D-Speed +a Wallbreaker beats stall. I still can't really tell. All I know is that it doesn't auto win as easily as D-Speed + Kyurem.
My Psychic Terrain team is honestly just full of gimmicky stuff I wanted to test out. Tusk wouldn't make the best hazard control mon for it because it already loses to hard to Rain Barry and Acrobatics Moon. The team also wasn't losing much to hazard stack despite only having Hat for hazard control.
They did say private match so could be challenge only custom game
You're right. Those two games specifically were custom. The rest has been gen 9 OU. Someone volunteered to help me test so I asked them to play stall. But I didn't give them any criteria for it and that's what happened.
I just assumed gen 7 because that's the only real metagame where there's both a good psychic terrain setter and mega evolutions
I wish it had Lele. The team uses Indeedee, which is really not that good.