Intro: This is my first ever post on the forums so sorry if this doesn't meet the guidelines or explain my choices well, I'm trying to learn more abt this. This team is an offensive team that with proper prediction can take down most things using quiver dance Volcarona, Toxapex is usually my starter because of toxic spikes, it can usually take at least 1 mon down with it while having set up toxic spikes, its good at stalling.
The Team:
Toxapex @ Leftovers
Ability: Regenerator
EVs: 252 HP / 88 Def / 168 SpD
Careful Nature
IVs: 0 Atk
- Baneful Bunker
- Recover
- Toxic
- Toxic Spikes
Toxapex is typically my team's starter to set up toxic spikes but other than that it stalls out opponents with toxic, recover and baneful bunker, I'm aware of psychic types being annoying which is why I added SpD EVs to somewhat counteract its weakness because the types it's weak to are mainly Sp attacks.
Garchomp @ Leftovers
Ability: Rough Skin
EVs: 4 HP / 252 Atk / 252 Spe
- Aqua Tail
- Stealth Rock
- Dragon Claw
- Earthquake
Garchomp is one of my wallbreakers with maxed Spe and Atk EVs to take down any tanks the opponent may have, I used to have choice scarf so it outspeeds everything but then I wouldn't be able to set up rocks and chose D claw over outrage for the reason of not being locked into a move.
Scizor @ Life Orb
Ability: Technician
EVs: 152 HP / 252 Atk / 104 SpD
Adamant Nature
- Bullet Punch
- U-turn
- Tailwind
- Dual Wingbeat
Scizor is probably my favourite Gen 4 mon, the reason I have it on this team is because stab Bullet Punch and technician is incredibly satisfying and U-turn is really useful and powerful, I have dual wingbeat for coverage and because of technician
Absol @ Life Orb
Ability: Super Luck
EVs: 76 HP / 180 Atk / 252 Spe
Hasty Nature
- Shadow Claw
- Throat Chop
- Psycho Cut
- Sucker Punch
Absol isn't really that good in the meta from what I've seen but when used well he is really powerful, base 130 Atk is really good and with sucker punch stab is even better, I recently added HP EVs so that Absol's frailty is somewhat better, a recent example would be not getting 2HKO'd by Suicune scald even including life orb damage.
Volcarona @ Heavy-Duty Boots
Ability: Flame Body
EVs: 16 HP / 188 SpA / 52 SpD / 252 Spe
Modest Nature
IVs: 0 Atk
- Bug Buzz
- Fiery Dance
- Quiver Dance
- Psychic
Volcarona is really powerful and arguably the best mon in the team, Heavy-Duty Boots is almost a requirement because it is 4x weak to stealth rocks and that diminishes survivability, 188 SpA almost guarantees at least a 2HKO on bulky psychics. If you find an opportunity USE QUIVER DANCE its one of the best boosting moves and can evaporate walls in the blink of an eye
Magnezone @ Choice Specs
Ability: Sturdy
EVs: 116 HP / 68 Def / 252 SpA / 72 SpD
Modest Nature
- Explosion
- Discharge
- Flash Cannon
- Thunder Wave
Magnezone is my answer to water types and flying types because in my opinion none of the other mons on the team are the best equipped to deal with them and that is really the only reason I have him here.
The Team:
Toxapex @ Leftovers
Ability: Regenerator
EVs: 252 HP / 88 Def / 168 SpD
Careful Nature
IVs: 0 Atk
- Baneful Bunker
- Recover
- Toxic
- Toxic Spikes
Toxapex is typically my team's starter to set up toxic spikes but other than that it stalls out opponents with toxic, recover and baneful bunker, I'm aware of psychic types being annoying which is why I added SpD EVs to somewhat counteract its weakness because the types it's weak to are mainly Sp attacks.
Garchomp @ Leftovers
Ability: Rough Skin
EVs: 4 HP / 252 Atk / 252 Spe
- Aqua Tail
- Stealth Rock
- Dragon Claw
- Earthquake
Garchomp is one of my wallbreakers with maxed Spe and Atk EVs to take down any tanks the opponent may have, I used to have choice scarf so it outspeeds everything but then I wouldn't be able to set up rocks and chose D claw over outrage for the reason of not being locked into a move.
Scizor @ Life Orb
Ability: Technician
EVs: 152 HP / 252 Atk / 104 SpD
Adamant Nature
- Bullet Punch
- U-turn
- Tailwind
- Dual Wingbeat
Scizor is probably my favourite Gen 4 mon, the reason I have it on this team is because stab Bullet Punch and technician is incredibly satisfying and U-turn is really useful and powerful, I have dual wingbeat for coverage and because of technician
Absol @ Life Orb
Ability: Super Luck
EVs: 76 HP / 180 Atk / 252 Spe
Hasty Nature
- Shadow Claw
- Throat Chop
- Psycho Cut
- Sucker Punch
Absol isn't really that good in the meta from what I've seen but when used well he is really powerful, base 130 Atk is really good and with sucker punch stab is even better, I recently added HP EVs so that Absol's frailty is somewhat better, a recent example would be not getting 2HKO'd by Suicune scald even including life orb damage.
Volcarona @ Heavy-Duty Boots
Ability: Flame Body
EVs: 16 HP / 188 SpA / 52 SpD / 252 Spe
Modest Nature
IVs: 0 Atk
- Bug Buzz
- Fiery Dance
- Quiver Dance
- Psychic
Volcarona is really powerful and arguably the best mon in the team, Heavy-Duty Boots is almost a requirement because it is 4x weak to stealth rocks and that diminishes survivability, 188 SpA almost guarantees at least a 2HKO on bulky psychics. If you find an opportunity USE QUIVER DANCE its one of the best boosting moves and can evaporate walls in the blink of an eye
Magnezone @ Choice Specs
Ability: Sturdy
EVs: 116 HP / 68 Def / 252 SpA / 72 SpD
Modest Nature
- Explosion
- Discharge
- Flash Cannon
- Thunder Wave
Magnezone is my answer to water types and flying types because in my opinion none of the other mons on the team are the best equipped to deal with them and that is really the only reason I have him here.
-> 
: As I said just above, Weavile is a way better choice over Absol because of all the Speed it brings (and this team definitively need more Speed Control) while having a super good Dual STAB. On this kind of Pokemon you don’t want to run four coverage moves (unless you use a Choice Band set) and thus I would opt for a Swords Dance set (even on Absol you rather run it with Swords Dance). I would just recommend using the standard Weavile set with Triple Axel and Knock Off as its main and powerful STABs and Ice Shard, which is a nice priority move to have, especially when you’re at +2. Heavy-Duty Boots are the item of choice on a Pokemon who may come often on the field and want to avoid the 25% damage on Rocks. Here is the set:
-> 
: Volcarona can be a cool sweeper but it’s not a Pokemon easy to fit in a team and you will need to have ways to deal with its main counters and especially the very common Heatran that completely walls it. If you really want Volcarona, I recommend using Roost over Bug Buzz as Slowking and Tyranitar are not that common nowadays and you’ll need Roost to beat some defensive checks. Anyway, here I think you’ll be better by replacing Volcarona for something with more utility. Tornadus-T could be a great Ground immunity and Defogger for a team that lacks both and can act as a Kartana check (because Scizor really struggles against Kartana). The moveset is super standard for a utility Tornadus-T and the Speed allows to outspeed Kartana and the 110 base Speed mons. Heavy-Duty Boots is of course the item of choice on a bulky pivot weak to Stealth Rock. Here is the set:
: You clearly don’t want to run no offensive move on Toxapex and let all the Steel types or Pokemon that don’t care about being poisoned come for free. You also want to run Haze on most Toxapex sets to avoid letting every sweeper setting up on you. Thus, I would change Toxapex movepool adding Scald as a way to fish for burns and chip down things and Poison Jab to be able to beat Tapu Fini in a one vs one scenario as the team struggles a bit against Tapu Fini, but also because it can help Weavile who has a hard time breaking through Fini. Poison Jab can also catch a Tapu Lele off guard for decent damage. Toxic Spikes are hard to make work because of the plethora of Heavy-Duty Boots users and huge number of teams running Slowking Galar or their own Pex and it is even harder when you can’t really pressure hazard removal. Regarding the item, having a Leftovers recovery can be great, even though in this case you want to run Black Sludge over Leftovers to annoy Trick users. I think Shed Shell would be a bit better here to avoid losing Toxapex against Whirlpool Tapu Fini as you rely a lot on Pex to check different top metagame threats, but also to be able to come in against Heatran on a Magma Storm and to let Garchomp in without taking damage on the incoming Taunt. I also changed a bit the spread, reducing a bit the SpD investment while keeping enough special bulk to come on scout Choice Specs Dragapult. You can keep your own spread if you want. Here is the set:
: I’m not a fan of offensive Scizor here, as it can only fit in HO teams, in my opinion, and would need Swords Dance anyway. Tailwind is also a rather bad move in singles, and you won’t benefit much from it. I think you’ll be better off with a defensive Swords Dance Scizor so that you can use it to sponge some Special breakers like Tapu Lele and Kyurem while benefiting from Magnezone eliminating some Steel types to become a threat late game with Swords Dance and Bullet Punch. Having U-turn + Swords Dance on the same Pokemon can seem weird but Scizor is one of the few Pokemon who often runs both because it needs U-turn to pivot out and keep up the momentum while doing decent damage and can thus use Swords Dance to either boost its next U-turn damage or become a threat with Bullet Punch. Lastly, I would go with Heavy-Duty Boots as an item on defensive Scizor just because you’ll come in regularly on the field and will struggle to check most things you are supposed to check if you take repeated Rock’s damage. Here is the set (the spread and can be adjusted but the SpD invest allows it to take 2 Specs Shadow Ball from Dragapult):
: Choice Specs Magnezone could work here, but I think you’ll rather have a Magnezone able to trap Ferrothorn as this Pokemon can be a bit annoying for the team. Hence, an Iron Defense + Body Press set could be a bit more efficient. Thunderbolt is your STAB of choice to hit Corviknight and Skarmory and last move could be either Toxic or Flash Cannon to punish Lando-T switch-in. Rocky Helmet is a nice item on this set to punish Corviknigth even harder by chipping it down on its U-turn. Leftovers are another solid option. As for the spread, you go drop some Speed to put more SpA, even though being fast means that you can trap fast Corviknigth spreads. Would probably test with less Speed and see how it goes (but you won’t at least enough Speed for no Speed Corviknight). Here is the set:
: Overall, your set is fine and here you can use Garchomp as a Stealth Rock setter because you have a Magnezone to trap and remove Corviknight meaning you don’t necessarily need a coverage move for it and you can punish it heavily for coming to Defog away your Rocks. You need Swords Dance however if you want to apply any kind of pressure with your Garchomp and can replace Dragon Claw by Scaled Shot which allow you to boost your Speed and became way more threatening or by a coverage like Stone Edge (with the famous EdgeQuake coverage). Here is the set (also your Garchomp didn’t have a nature, but Jolly is of course the one of choice):
and 
: Dragapult is not that hard to deal with, but you will still need to be careful against it as the way you want to beat Specs Dragapult is by going into Toxapex to Scout the move it uses. Scizor can take two Shadow Ball but will eventually get SpD drop and dies to Flamethrower. Weavile can also help against a Pult locked on Shadow Ball when Toxapex is low in health. Blacephalon is a bit harder to deal with defensively because it hits significantly harder (unless it’s scarf Blacephalon). However, unlike with pult you can outspeed it with Tornadus-T and Weavile and just need to make sur you don’t let it come in for free. Toxapex can still scout the move it uses, and you can switch into Weavile if it decides to lock itself on Shadow Ball, but Weavile is not gonna take it well.
: Buzzwole mainly runs defensive sets, but as it walls both Weavile and Garchomp, it can be pretty annoying to beat and you want to really on Toxapex + Tornadus-T, to take its hit and force it out. It is definitively a hard matchup for this team, and you’ll have to be patient in order to make progress against Buzzwole teams.
: As Garchomp is the Ground type here, Tapu Koko is a big threat, and you should be super careful with your scizor as it’s your only reliable answer to it, so keep it out of range of double Thunderbolt. In the same way, Zeraora could be a threat, but Garchomp is still a bit hard to break for it.