Welcome to smogon! I think your post seems to be misguided with a few things that Kyurem can actually do in the metagame, so here' a few criticisms of your post.
- Dealing with Kyurem:
Kyurem is never an issue to deal with because its typing is *weak*. I don't understand why people believe his typing to be versatile or good by any means. Dragon is already good against dragon so it doesn't make him a better match up against dragon types. It doesn't make Kyurem a better match up against fairy types, it barely makes him a better match up against other ice types. He is stronger against grass but grass is already at a disadvantage against dragon. He is stronger against flying. He is stronger against ground. You get the point.
However, these minor advantages don't make up for the fact he becomes weak to fighting, neutral to fire, neutral to ice (which isn't a disadvantage but a "benefit of being an ice type"), weak to steel which was always a bad match up made worse, and rock which... yikes. Dealing with Kyurem is easy. You have two ways to build him which makes him versatile but due to the lack of resistances it really boils down to crossing your fingers that they make a few bad moves so you can set up to "sweep". I've had no issues dealing with Kyurem regardless of the team I've used recently because Icicle Spear on anything but Cloyster sucks. Let's be real: I'm going to swap into a steel type and you're going to lose a turn dealing with that fact because you don't have good moves to deal with it and that's exactly what I did.
Personally i feel that looking at Kyurem through the lens of a dragon pokemon doesn't tend to be a particularly useful analysis, but more to the fact that it's a powerful ice type pokemon with the added resistances of a dragon type. There's a reason why basically every other ice type used in OU are very frail and tend to only be used for breaking/sweeping with good offensive stats (think Weavile, Arctozt and Mamoswine, Ninetales-A is an exception due to how busted Aurora Veil is). Ice is a terrible defensive typing, but Kyurem having an added dragon type gives it a crucial resistance to water, allowing it to usually come in on water types and using them for setup or simply trying to break through them.
There are not only two ways to build around Kyurem, there are a variety of sets that all have a different list of checks and counters, the main sets include:
Sub Roost 2 Attacks
Sub DD
Specs
Never Melt Ice
Scarf (imo the worst set)
https://pokepast.es/93fe90c58fad56a7 (Sets)
The notion that icicle spear sucks on anything but Cloyster is fairly misguided, but I'll explain in more detail with your post talking about pressure.
Now I'll take a look at Kyurem for myself and I'll give my full step by step.
- Preparing my Kyurem:
I start off looking at abilities. Okay. Pressure. Pressure is awful. Anyone who says Pressure is a useful ability probably thinks Toxic on Salazzle is too OP.
While I would agree that Pressure is usually a useless ability on most legendaries, apart from like, Suicune, Kyurem's stats and Movepool allow it to abuse it very well.
There are two kinds of set that mainly aim to abuse Pressure, Sub Roost 2 Attacks as well as Sub DD.
These sets aim to get opportunities to sub up and use pressure to wittle down the pp of pokemon effectively.
For example, SpDef DD Kyurem can use it's great bulk in conjunction with substitute and roost to stall out pokemon like Clefable which should in theory be able to counter it. The reason why sub DD tends to do this even better than sub roost is because of the crazy 48pp that icicle spear has, which makes it a very spammable option while under a substitute, allowing it to effectively outstall a Toxapex.
Now for the items. One recommendation is the Heavy-Duty boots but an item slot to prevent potential hazards for just one pokemon is a waste. Another recommendation is leftovers. Leftovers are solid because of the bulk... but did I just hear "make use of pressure" and "stalling"? Roost is great, truly, and Kyurem's HP is magnificent but are we forgetting that other sweepers exist? Kartana pops up to Kyurem as a two free buffs and one less pokemon for the opponent.
Heavy-Duty-Boots is absolutely not a waste on Kyurem, taking 25% every time you switch into rocks is very substantial and means you can substitute one less time, making it generally better than leftovers.
Against a usual substitute stall Kyurem, if Kartana comes in that usually means that either:
1. Kyurem just killed a mon
2. Kyurem has a substitute up.
In scenario 1, great, Kyurem accomplished something, in scenario 2, Kartana can't immediately hurt Kyurem, which basically means Kyurem can just go for free damage and then switch to the Kart check.
Enough ranting, let's go ahead and add those leftovers. Now we have our pokemon. We're going with the recommended physical sweep build + leftovers to make use of bulk. Let's go right into the battles. I'll share my results with minor changes to Kyurem as I go.
The results:
Battle 1: Swapped Kyurem up against a burned Mamoswine dragon danced twice. They swapped in Tapu Lele and did 90% with one "unbuffed" psychic. Doesn't seem like I'll be PP stalling anytime soon but I didn't need to. I got lucky with Icicle Spear and took out Tapu Lele and swept his team with just Kyurem. Kyurem v Toxapex, Mamoswine, Tapu Lele, Corviknight.
Status: Swept
Battle 2: Kyurem (with 2 dance stacks) took out two pokemon before getting one shot by a Scarfed Barraskewda with Close Combat.
Status: Lost, but Kyurem was still useful.
Battle 3: Kyurem got Body Pressed.
Status: Fodder.
Battle 4: Kyurem v Clefable won. Kyurem lost to Mimikyu Shadow Sneak priority.
Battle 5: Revenge killed Volcarona. Kyurem lost to Ferrothorn Gyro Ball after dealing 20% with Icicle Spear from +1 Dragon Dance.
Not only do we not have replays to see the context behind these games, but a lot of them seem don't seem to show much?
G1:
252 SpA Choice Specs Tapu Lele Psychic vs. 56 HP / 0 SpD Kyurem in Psychic Terrain: 313-369 (77.2 - 91.1%) -- guaranteed 2HKO
Saying it's "Unbuffed" is slightly deceiving here, it's a specs psychic under psychic terrain, obviously it's going to do a lot, doesn't mean Kyurem can be an effective pp staller. But it also shows that you did sweep with Kyurem.
G2:
Scarf Barraskewda? You mightve been playing against rain, which activates Barraskewda's swift swim, even then it killed two mons and you decided to let Kyurem die, this doesn't show Kyurem being bad.
G3:
... ok? Kyurem died to a fighting move, this would definitely need context to show Kyurem not being up to par.
G4:
Mimikyu has a 0.462% usage rate, meaning that you would basically see it once every 200 games. While the Mimikyu matchup doesn't seem especially important, your Kyurem here was able to kill a Clefable, which usually has the type advantage on it. You leaving it in on a pokemon that basically always runs priority is still on you.
G5:
Why would you keep a Kyurem in on a Ferro without a Sub, this one definitely seems on you.
All of your examples don't show ways that Kyurem isn't broken, they show Kyurem killing things, and then dying to stuff it obviously dies to. Preserving your Kyurem obviously would give your Kyurem extra setup opportunities.
My overview because it's late:
Kyurem has plenty of counters and while its stats are versatile, his moveset is not. His ability does not make up for his weaknesses and his typing makes him weak to really strong pokemon already. He is neat but weaker than Kartana, Volcarona, and many other sweepers that have much more going for them. Kyurem is carried by his stats which keeps him from being bad, so he's "decent" but not uber worthy.
P.S. Yeah two focus blasts from Kyurem against Scizor would be pretty strong. One fiery dance from Volcarona is pretty strong too. Scizor is good to get a good Sword Dance in before potentially sweeping with Bullet Punch which Kyurem also loses in 2 shots to
Main post.
Kyurem does not have plenty of counters, the most consistent one being Scizor and Blissey both fold to Specs Focus Blast, the only "true" Kyurem counter would probably be like... Shedinja.
Bulkarona is also a viable option, but can be afraid of Specs variants with Draco Meteor.
The last remark on the fact that Volcarona deals with Scizor better than Kyurem is... irrelevant, blanket counters to ice types are steels, and Scizor is the only viable one that isn't weak to Ice moves + Earth Power or Focus Blast, and even then it still gets 2 shot by Focus Blast.