Well i dont normally post on these type of forums but I am bored enough to do so this time. So the mons brought up were:
For what its worth other Pokemon that people mentioned included Mega Glalie, Sigilyph, and Scrafty,
The main Pokemon that has been brought up by the council and pushed for most extensively is Tyrantrum
Tyrantrum: Well without a doubt this mon is a powerhouse capable of 2hkoing allot of the tiers top walls with the banded set, simply being a powerful revenge killer in its scarf set, or being a great wc in its DD lum or lo set.
Alomola:
252+ Atk Choice Band Tyrantrum Head Smash vs. 232 HP / 252+ Def Alomomola: 319-376 (60.3 - 71%) -- guaranteed 2HKO after Leftovers recovery
Amoongus:
252+ Atk Choice Band Tyrantrum Head Smash vs. 252 HP / 160+ Def Amoonguss: 382-450 (88.4 - 104.1%) -- 31.3% chance to OHKO
Tangrowth:
252+ Atk Choice Band Tyrantrum Head Smash vs. 248 HP / 252+ Def Tangrowth: 237-279 (58.8 - 69.2%) -- guaranteed 2HKO after Leftovers recovery
Offensive playstyle checks:
Siesmatoad:
252 Atk Tyrantrum Head Smash vs. 164 HP / 0 Def Seismitoad: 148-174 (37.7 - 44.3%) -- guaranteed 3HKO
Scrafty:
252 Atk Tyrantrum Head Smash vs. 0 HP / 0 Def Scrafty: 103-122 (38 - 45%) -- guaranteed 3HKO after Stealth Rock
Qwilfish:
-1 252 Atk Tyrantrum Head Smash vs. 252 HP / 252+ Def Qwilfish: 135-159 (40.4 - 47.6%) -- 2% chance to 2HKO after Stealth Rock and Black Sludge recovery
magneton:
252 Atk Tyrantrum Head Smash vs. 0 HP / 4 Def Eviolite Magneton: 81-96 (33.6 - 39.8%) -- guaranteed 3HKO after Stealth Rock
Now with that in mind there are still mons who can counter/check it decently even when banded such as bronzong, rhyperior, mega steelix, etc.
Tyrant has a decent enough typing to setup on a few mons of note such as alomola, choice locked emboar, choice locked delphox, etc.
That gives tyrant a chance to setup on not only offensive playstyle, but also on the more defensive ones. From whats seen above you can tell that on paper allot of offensive teams can run intro troubles with a tyrantrum whether or not its scarf:
flygon:
252 Atk Tyrantrum Head Smash vs. 0 HP / 0 Def Flygon: 140-165 (46.5 - 54.8%) -- 65.2% chance to 2HKO
Virizion:
252 Atk Tyrantrum Head Smash vs. 4 HP / 0 Def Virizion: 153-180 (47.2 - 55.5%) -- 75.4% chance to 2HKO
About the only thing that's somewhat holding tyrantrum back versus offensive teams is its speed but that can simply be mitigated by a scarf (which restricts it in that manner). The mon itself relies on its shaky move known as headsmash with a whopping 150bp but with a 80% accuracy baseline. This talk is really just to highlight the rex's strong points given to it by its ability to 2hko a good portion of the tier unboosted while at the same time boasting decent natural bulk and typing. As a stall player there are times where I feel pressured by its presence on another team but its honestly negligible, but as an offensive player I can see it being a huge pain to deal with since everytime it comes in i force myself to take dmg on walls that are normally supposed to be used to block multiple mons in the tier which usually are paired up with tyrantrum. If offensive checks were more pronounced I would feel it would be fine for it to be in the tier but currently I want to say it gets in the way at times. But again this is all my opinion and I probably missed out on allot of mons since I am making this post when i woke up.
Id still like to hear what others think.