First,
Lcass4919, if you're going to address my arguements and points, have the respect to address me by name, please.
Second, your logic of "we can't suspect Kyu-B because it's not as common" is pretty, well... I'll be blunt and say bad. Most other -ates are not common either. Since Diancie and Ray are the only common ones... should we suspect the Pokemon instead? Heck no. Additionally, we already have precedent for suspecting the weaker of a suspect trio at the same time. Specifically, when Mega-Rayquaza was suspected along with Primal Groudon and Primal Kyogre, but was not banned while the others were. And finally, before those two arrived on the scene, Kyurem, along with -ate Xerneas and Yveltal, were dominating the X/Y meta before ORAS. Considering the only thing that's changed, and remained unbanned, for Kyurem, in ORAS outside those two are Mega-bro and Mega-Audino, neither of which are really enough to change its impact on everything else It basically just means you can use something other than Furcoat Chansey or Registeel to wall them. But, considering Mega-Bro can't handle Kyu-W (Boomburst if not Soundproof, Seed Flare if it is), you pretty much only have Mega Audino, who I have doubts would be able to handle the more flexible movesets of Kyurem since it's not forced to run Fake Out + Extreme Speed + Boomburst on standard sets. Hence, there's little reason not to suspect along with the others, despite Refrigerate being "less common" or "weaker".
no, we cannot suspect kyurem YET. without accurate results, we are only banning because of our "personal bias" and not factual laddering. kyurem isnt nearly used as much as the other two, so suspecting it is pointless in terms of getting RESULTS. we dont ladder during suspect tests solely to show off how much better we are, its so we can "Test the suspect" which is pointless when the current meta spams ate as it is, and kyurem does NOT get as much usage. not nearly enough to get accurate results. if we suspect the three togeather, we are just bandwagoning refridge. when we should focus on the two "bigger ones" in terms of usage/better abusers, THEN look into the "younger brother". nowhere have i said not to suspect it because its not as common. my point is if we are going to suspect refridgerate, i want to actually see people USE REFRIDGERATE. which next to noone will, since this is PROVEN IN THE META. im sorry for accidentally jabbing you, but i was literally trying to explain this very misinformation in that exact post your arguing.
And third, Fairy/Rock is a pretty bad typing. Seriously. Here, lemme run numbers on the two using Diancie's resists. I'll be accurate and use standard Diancie and standard Kyurem-B, as listed by Smogon itself. (Not calcing Kyu-W since it doesn't have a listed standard, although I suspect it's running similar EVs when not using a Scarf set.)
So, let's first compare Fire using the premiere Fire-type attacker.
252+ Atk Primal Groudon V-create vs. 0 HP / 0- Def Mega Diancie in Harsh Sunshine: 318-374 (131.9 - 155.1%) -- guaranteed OHKO
252+ Atk Primal Groudon V-create vs. 240 HP / 0 Def Kyurem-B in Harsh Sunshine: 619-729 (137.2 - 161.6%) -- guaranteed OHKO
Neither survive, of course, but very little does to Groudon's V-create. But either way, those numbers are curiously close, huh? And, seems Diancie's resistance to Fire is pretty useless. So, let's move on to Normal!
stab v-create from sun boosted pdon ohkos diancie...wow...its not like it 2hkos giratina too or anything right? right? 150/120/120 bulk 2hkoed. yup. this calc shows a lot in terms of fire type moves diancie can tank...like rays magma storm upon switchin. but no, diancie HAS to get nuked by pdon and its nuke-create. im sorry for sarcasm, but seriously?
252+ Atk Regigigas Facade (140 BP) vs. 0 HP / 0- Def Mega Diancie: 150-177 (62.2 - 73.4%) -- guaranteed 2HKO
252+ Atk Regigigas Facade (140 BP) vs. 240 HP / 0 Def Kyurem-B: 294-346 (65.1 - 76.7%) -- guaranteed 2HKO
Nope, both a guaranteed 2HKO with standard Kyub taking a whopping 3% more damage. So, Diancie's resistance to normal doesn't save it against one of the best Normal-type attackers. What about Dark?
252+ Atk Mega Tyranitar Knock Off (97.5 BP) vs. 0 HP / 0- Def Mega Diancie: 106-126 (43.9 - 52.2%) -- 15.6% chance to 2HKO
252+ Atk Mega Tyranitar Knock Off (97.5 BP) vs. 240 HP / 0 Def Kyurem-B: 207-244 (45.8 - 54.1%) -- 50.8% chance to 2HKO
That 40% more likely chance to get KOed here looks frightening but... Knock Off, so the next hit is doing pitiful damage to both. Crunch, Dark Pulse, and Night Daze would do more but, in my experience, almost all offensive Dark-types run Knock Off as their only Dark-STAB. Either way, a whopping 2% difference here! So, Diancie's Dark-resistance is kinda meaningless. Flying?
252+ SpA Mega Rayquaza Oblivion Wing vs. 0 HP / 0 SpD Mega Diancie: 84-100 (34.8 - 41.4%) -- guaranteed 3HKO
252+ SpA Mega Rayquaza Oblivion Wing vs. 240 HP / 0 SpD Kyurem-B: 201-237 (44.5 - 52.5%) -- 20.7% chance to 2HKO
Here it actually kinda makes a difference. But what gives? I'm running Hasty Diancie, Naive is also standard as well, which would add a bit wider, but not big difference, to Diancie's above damage values. (Would avoid a 2HKO from T-Tar guaranteed if it somehow got another item.) Kyu-B is also a little less bulky specially. Converserly, however, Kyu-W swaps Kyu-B's defense and special defense, so, if I were to compare Kyu-W, the values would be closer. Even still... an 11% difference on a
resisted vs neutral hit is pretty much crap for the former. (And regardless, it's kind of a wash since both Diancie and Kyu-B utterly murder Mega-Ray, Kyu-B especially even if Ray has King's Shield.)
Not doing Bug because Bug-STAB doesn't really exist in BH except maybe for the rare U-turning Scizor. Nor Dragon since immunity is immunity. Not going to compare Kyu-B's resistances to Diancie since that's a little unfair. Also, as we can see, Diancie would be struggling to survive neutral hits that Kyu-B could shrug off.
As for the raw typings itself in a vacuum against BH...
Rock/Fairy
Resists: Normal, Flying, Bug, Dark, Fire - Four of these are pretty relevant to BH.
Immune: Dragon - Relevant, but, oddly, not a lot of Dragons actually use their Dragon-STAB. It's more Contrary-proofing than actually dealing with Dragons. Ray and Kyu-B need other coverage, except the very rare Technician Kyu-B who might run Dual Chop. Latis run it, but both Diancie and Kyu-B check them pretty hard. Palkia, Reshiram, and Sceptile like Dragon-STAB on some sets, but they're not common. Dialga usually goes Imposter-proof with Doom Desire, AFAIK
Weak: Ground, Steel (4x), Water, Grass - Ground is a big one, and Steel being 4x means some stuff is running random Steel moves just to bop Diancie since it can't survive any of them. Water, while more restricted, means Kyogre can punish this type hard with a single shot, and a failure to KO Gyarados or Palkia in one shot means they'll be destroying Diancie. Grass is rare, but some Pokemon, like Kyu-W, like running stuff such as Seed Flare to snipe Kyogre and Mega-Slowbro. Sceptile likes using Grass too, especially on Sheer Force and Contrary sets.
Ice/Dragon
Resists: Water, Grass, Electric - Between Water-resistance and Bolt Strike, Kyurem is pretty much a giant middle finger to Kyogre and can be comfortable dealing with Gyarados and some Palkia sets. Grass, again, is rare, but it helps Kyurem switch into opposing Kyu-W coverage and deal with Sceptile. Electric isn't overly common, but less damage from Volt Switches is always handy, especially since it's likely to do a little more damage than U-Turn since people aren't zeroing out their Special Attack to minimize stray confusion and Foul Play damage.
Weak: Fighting, Rock, Steel, Dragon, Fairy - Fighting isn't too relevant to the tier, being basically the domain of Xtwo, Gengar's coverage, and the stray Low Kick. It hurts when it's there, but it's not all that common. Some Contraries run Close Combat, but most don't have room for it. Rock is more relevant to Stealth Rock, and is a shared weakness with Mega-Ray. Some stuff run random rock moves for Mega-Ray, which will hurt Kyurem, but aside from Stealth Rock, it's not all that common. And for SR, standard Kyu-B runs HP EVs that let's it switch in 4 times while still having HP left, which is worth noting. Kyu-B shares a Steel weakness with Diancie, but it's only half as weak, so it tanks the hits a heck of a lot better. It can still hurt though (looking at you, Dialga). Dragon is relevant but, as said above, outside of Contrary, not many Dragons actually run Dragon-STAB. Typically only things that have a bad STAB-combo anyway, like Lat@s or Sceptile. Of these, Fairy is the biggest one because of Pixelate. But, if Pixelate is banned, this weakness will become a heck of a lot less detrimental since it no longer needs to fear Fakespeeds or Boombursts. Rather... Moonblast, Light of Ruin, and the stray Play Rough, all of which are sigificantly weaker and can be Fakespeeded over (except bulky Xerneas, though Kyu-W can still probably just Boomburst that to oblivion.)
Basically, in a vacuum, Diancie's resists are a bit better, but Kyu-B's are by no means bad. Immunity is an immunity and is the major advantage. Kyurem has one more weakness, but Diancie's overall are a lot more common as coverage and a lot more crippling since it has a 4x weakness. But out of the vacuum, Diancie's weak bulk, made worse on its standard sets by its Nature, means it gets bopped pretty badly by just about anything regardless, with its resists pretty much meaning "oh hey, it's something I
don't get OHKOed by!" All it really has in practice is a Dragon-immunity to protect it from significant damage.
its somewhat annoying that your using a -attack and 240 hp variant comparason (even though its justified due to being their main sets) but i will agree that fairy/rock is a bad typing for diancie....but its not a bad typing...diancie is just a glass cannon. the two have no relation whatsoever.
And finally, as I showed in my last calc above, Kyurem doesn't struggle with Kyogre. Rather, Kyogre struggles to survive a Bolt Strike without running Fur Coat.
"this is "stab vs stab" obviously, and you have to take into account coverage...but even then...kyurem is picked off by WAY more common coverage moves then diancie is." i literally addressed this when you said it i mean, diancie beats its checks with tarrows too...so i dont see your point. especially when most run moonblast and 2hko kyurem(since they run speed nowadays) at most, id say it handles its checks no better/efficiently then the other two does.