All of Palafin, Roaring Moon, and Espathra are more warping than people are letting on and if it were up to me I wouldn't even let their names be mentioned. For me they have to solve more issues than they cause for an overall net positive, otherwise it's just adding an additional constraint to the teambuilder. Alternatively they have to be so obscenely bad post-Tera that they don't seriously impact the health of the tier 99% of the time (re: Regieleki). You couldn't claim this for Deoxys-S, you absolutely can't for Palafin and Roaring Moon, maybe Espathra??
On Palafin:
The four most controversial threats at the moment are Mega Charizard-Y, Dragapult, Gholdengo, and Kingambit. Palafin doesn't hard check any of them. For Yard, it barely switches in and has to be Choice Band / Have Yard take Rocks chip and be in Hero form against a playstyle that features very threatening Palafin checks such as Raging Bolt, Slowbro, Kartana, Solar Beam clickers, etc and finds it easy to position these things against Palafin. Dragapult can punish Palafin coming in via Z-moves, Specs nuking it, or it being Wisped and crippled while Palafin has to safely come in and not die after scouting against Wisp and kill with Banded coverage (Throat Chop / Ice Punch). Gholdengo is checked offensively by Choice Band, Bulk Up just loses unless the Ghold player is throwing the game. Kingambit is a tossup since you're forced to run the same Sucker Punch mind games that plague the rest of the tier if you're not Sub Bulk Up.
It checks nothing controversial, instead it can abuse defensive staples fairly hard. Alomomola and Toxapex absolutely stink into Bulk Up variants, while Banded Palafin will just Flip Turn out or deal obscene damage under Rain if they're in the sixty percent or less range. Great Tusk, Gliscor, Landorus-T are all slower and get turned into fodder for both variants, making it a detriment to perform standard utility jobs without being punished for it. Ferrothorn, Zapdos, and Zamazenta aren't "great" answers either. Ferro constantly has to play prediction games against Choice Band for fear of Close Combat and it doesn't win against Bulk Up variants, Zapdos doesn't win against Choice Band because it hits too hard, Zamazenta requires fairly pristine conditions to check Bulk Up and it can't switch into Choice Band either. Offensive staples like Tapu Koko, Iron Valiant, Mega Lopunny are also very tossup since Choice Band will deal heavy damage via Jet Punch. They can also just lose if Bulk Up is boosted.
As we've established Dragapult checks it, as does Ogerpon-W and Raging Bolt consistently. These seem to be the only common ways of dealing with it consistently unless you willingly move to less than great options like Kartana, Rillaboom, Mega Venusaur, etc. Tapu Lele can beat Bulk Up sets I think since it runs Jet Punch + Drain Punch only iirc but its inability to switch into Choice Band whatsoever is a major detriment. I rate things like Rotom-Wash and Mega Latias high but there isn't a great consensus on if these guys are actually good picks to be running in general. Wouldn't want them forced on for Palafin specifically.
Is Palafin's presence a worthwhile investment long term?
On Roaring Moon:
A more favorable outcome in terms of benefits: It's a fairly ok switch in to Yard (in the same vein as Offensive Garchomp) and can capitalize off of the opponent's Sun with Protosynthesis. Nice offensive check to Gholdengo as well although nothing stops the Ghold player from switching out depending on the composition, more case-by-case dependent. Same goes for Kingambit but worse so since it requires Earthquake to beat it and you can't be too low on HP. It does not consistently check Dragapult at all since Pult is faster and outpaces Choice Scarf sets after a single Dragon Dance boost.
Roaring Moon simultaneously checks Yard and is one of its best partners, akin to Raging Bolt, so it ultimately perpetuates Sun's impact on the metagame and makes the playstyle harder to respond to. I also concur with Slopcat's take that Roaring Moon would be a frustrating force on Hyper Offense teams since Dragonium Z + Earthquake still mauls a large portion of the metagame. Zamazenta, Alomomola, Lando-T, Great Tusk aren't real checks because of this. Either is Heatran or Toxapex. Ferrothorn can't really win unless it runs Gyro Ball or Body Press since Taunt will shut it down. Offensively Tapu Koko, Tapu Lele, and Mega Diancie all can't work as checks due to Earthquake or Knock Off hitting too hard in Lele's case. Urshifu-RS and Mega Lopunny unfortunately have Lose to Dragon Dance Syndrome as well.
As for what actually checks this, I would say it's only a select group of Fairy and Steel-types + Weavile. Iron Valiant and Clefable are undoubtedly strong checks to Roaring Moon provided it doesn't run Iron Head to shore up this weakness, with this in mind nicher options such as Enamorus and Tapu Fini work nicely to check it as well. Mega Scizor and Melmetal can also shrug off Earthquake and take it out with U-Turn/Close Combat and Double Iron Bash respectively, while the aforementioned Ferrothorn from the second paragraph can again win if its Gyro Ball or Body Press (or if Roaring Moon isn't Taunt/Sub). Weavile can work as an emergency revenge killer but its not something you can use to switch into Roaring Moon obviously.
In my eyes this is more acceptable than Palafin but still seems risky to free.
On Espathra:
It doesn't check any of the controversial threats really. Granted you can cheese your way through Yard, Pult, and Ghold given enough boosts but that's not consistent whatsoever. So when people say it provides nothing to the meta on this point they are not just saying it without basis.
We have five good Dark-types in this metagame: Mega Tyranitar, Weavile, Kingambit, Samurott-Hisui, and Ting-Lu. Of those five, Espathra can overpower two of them "naturally": Weavile and Samurott-Hisui. So that is a pretty large part of the theoretical pool of checks removed. Mega Tyranitar and Ting-Lu are things that work but they can technically fold to Z-Espathra or get cheesed by Hypnosis variants. This leaves only Kingambit for right now as the sole consistent Dark-type check. Steel-types such as Iron Crown, Heatran, Treads, and Kartana don't win if it's boosted too much and it can even use the first three as setup opportunities. To anything that doesn't resist Espathra, they just don't win consistently ever. Everything has scenario specific conditions at that point.
Hope is not all lost however. The post-Tera scene does make things such as Melmetal (as said above), Ferrothorn, and Mega Scizor better at checking Espathra. Outside of that the pool of consistent checks seem kinda barren?? Only other things I'm seeing are like Victini and Mega Mawile? Idk lol I wrote this post thinking it would have more checks so if people could point some out that aren't like shitters then that would be cool. Otherwise, I don't think being pressured into running Kingambit for the millionth time or some select Steel-types to avoid being fished by Espathra is an indicator of a balanced pokemon. If it had more checks then yes my tune would change obviously but you can't just slap Kingambit on every team ever and call Espathra balanced.
I don't think I would even try with Espathra, it seems like an annoying matchup fish (such as Polteagiest) at best and very uncompetitive at worst. There is no scenario where it's ever in between.
Vlarcheops 
