So, Toxtricity. Arguably the strongest wallbreaker in the tier. What's your best counterplay against it and how reliable is it? Well, let's see.
: This is probably the most obvious answer. Pallosand is immune to Boomburst and Volt Switch, can use a SpDef spread to avoid the immediate OHKO from Snarl with Spikes up, and takes resisted damage from the odd Sludge Bomb. However, SpDef Palossand is not the best special wall in the tier; not by a long shot as it tends to struggle with most other common special attackers. Rotom-H can Tera Blast Water, Kilowattrel can also Tera it or simply throw out Hurricanes for decent chunks, and the likes ot Tatsugiri, Arboliva, and Rotom-Mow naturally do well against it unless it were to Tera. However, if Palossand decides to Tera, it will lose the Boomburst immunity it relies on to check Toxtricity. So, Palo is relatively reliable at handling Toxtricity, but it has to run SpDef to be safe against Specs Snarl and is generally overwhelmed by other common special attackers in the tier if it goes this route, which means you're likely using Revavroom, Blissey, or some other special tank alongside it.
: The age old answer to pretty much any brute force special attacker, it shouldn't come as a surprise that Blissey pops up as a check to Toxtricity. However, Blissey lack a Volt Switch immunity and will generally need to be paired with 1-2 Pokemon that are immune to it as a result. This results in some dangerous 50/50s for the Blissey user as switching to their Volt Switch immunity on Boomburst is resulting in a dead mon unless it's Palossand. Alternatively, switching to Blissey on a Volt Switch keeps the Toxtricity user in the driver's seat and it's not like clicking Boomburst on an incoming Blissey is a bad plan, especially if Toxtricity is already Tera Normal as it does 43% minimum, meaning a mandatory Soft-Boiled to avoid the 2HKO on next switch in, which means the Toxtricity user is still in control despite Blissey tanking Boomburst. Blissey has the option to Tera Ghost, and if it does this, it basically becomes impossible for Toxtricity to KO and a well-timed Thunder Wave on an already Tera'd Toxtricity will result in it being outsped by virtually everything and rendered much less useful. Overall, Tera Ghost Blissey is probably the safest way of dealing with Toxtricity, but considering how much Blissey tends to love Tera Fairy for the Fighting and Dark resists, there's certainly an opportunity cost to using this Tera type in order to better handle Toxtricity.
: The 2 SpDef Steels that aren't weak to Snarl are certainly capable of switching into Boomburst once... however, that's the problem for them. They're soundly 3HKOed WITHOUT Toxtricity needing to Tera and their lack of reliable recovery means that Toxtricity will break through them next switch in unless they're Tera Ghost, in which case, Toxtricity can simply Volt Switch to chunk them. So yeah, I'm not really counting our Steel types as options to handle Toxtricity as, even if they Tera Ghost to dodge Boomburst entirely, they're still Volt Switch fodder
I'd list Mudsdale, but it takes 83% minimum from Boomburst. Definitely not a switch in. So, it's pretty obvious that defensive counterplay to Toxtricity is pretty limited thanks to its raw power. Does that make it broken? Not necessarily. Throughout the history of RU, there's been plenty of offensive threats capable of tearing up slower teams with relative ease. BW had Druddigon and XY/ORAS had Exploud just as examples, however I want to focus on Exploud as the comparisons are quite good with it and Toxtricity. Both spam Boomburst and resisting the move typically isn't enough as slower resists are easily 3HKOed for the most part, which makes it a real challenge to deal with defensively. However, what about offensive counterplay? Are there offensive Pokemon capable of switching into at least one of its moves once and snatching back momentum from the Toxtricity user? As it turns out, yes there are... well, kind of.
: Chief among these is Gardevoir as its Trace ability means it will also gain Punk Rock and actually reduce the power of Toxtricity's best move, Boomburst, to such a level that Toxtricity needs to win a messy 50/50 based on Tera. Assuming Toxtricity has not yet Tera'd, it still does enough to 2HKO Gardevoir on the switch, but is obviously outsped and OHKOed by Psychic. If it Tera's to Normal, it drops the Psychic weakness, dodges the OHKO, and KOs back due to Gardevoir taking Boomburst on the switch. However, Gardevoir could also Tera to Fairy and threaten a near OHKO with Moonblast if Toxtricity Teras as well looking to dodge the OHKO from Psychic. The availability of Tera obviously can swing this in favor of either participant. The big reason Gardevoir is so solid as an offensive response is that it commonly runs Scarf and has a higher Speed tier than Toxtricity, meaning that sneaky Scarf variants of Toxtricity can't get one over on it like Scarf Toxt can with most other offensive threats.
: As a faster Ground-type, Krookodile is quite capable of leveraging its immunity to Overdrive and Volt Switch in order to force out Toxtricity or swiftly KO it with a powerful STAB Earthquake. Of course, Krook has nowhere near the bulk needed to handle Boomburst and is absolutely screwed if it turns out that Toxtricity is Shift Gear and it sets up on the switch to suddenly outspeed even Scarf Krookodile. Worth noting that the secondary Dark typing lets Krook resist Snarl as well should its team feature a Tera Ghost Pokemon, such as Blissey or Revavroom. So Krook isn't bad, but it is OHKOed by Specs Boomburst and will absolutely have the tables turned on it by a Shift Gear on the switch.
: With its sky high base 125 Speed and Volt Absorb ability, Kilowattrel can happily switch into a Volt Switch or Overdrive to stifle Toxtricity's momentum. However, much like Krookodile above it, its frailty and lack of a Boomburst resistance leads to it having similar issues. This can be remedied by utilizing Tera Ghost as the Tera obviously does not rid Kilowattrel of its ability of Volt Absorb and also makes it immune to Boomburst. The issue with this is that Snarl is still an OHKO after Tera and Ghost Tera also doesn't really aid Kilowattrel offensively as it generally will prefer Water to supplement its STABs. So, similar to Krookodile, Killo does a great job of deterring Toxtricity from using Volt Switch or Overdrive, but it will need something else to deter Boomburst as it has no hope of surviving it.
As you may have noticed, there's no offensive Boomburst resistance listed... uh, that's because there are none pre-Teras. Even Gardevoir, the rare case of an offensive Pokemon not being OHOed by Boomburst takes 47% minimum, meaning it is 2HKOed with Stealth Rock up and there's often no immediate way to offensively punish a Toxtricity using Boomburst as there's simply a void of faster Pokemon that resist the move to stomach it once and take back momentum from Toxt. This is also primarily only accounting for Choice Specs sets as Toxtricity is perfectly capable of using Throat Spray Shift Gear or Choice Scarf sets effectively. Shift Gear may not be able to throw out Boomburst immediately like the choice sets can, but its not like our Grounds are good initial switch ins, which means it can pretty freely throw out Volt Switches early to maintain / gain momentum. The Scarf set, while uncommon compared to Specs in particular, shores up the offensive matchup issues Toxtricity can run into as it can simply use some of its key resistances and "good enough" bulk to take at least 1 resisted hit to find its way in and harass opposing offensive teams make it more versatile and dangerous than XY/ORAS Exploud, the subject I feel many veteran RU players will compare it to. It also doesn't help that the tier is pretty limited in offensive Steel and Rock types that aren't completely run over by Toxtricity's Electric STAB moves and it's not like Toxt will be complaining if it's forced to use Volt Switch early on due to something like Blissey or a Tera Ghost mon is present to hinder its Boombursts.
Does this mean Toxtricity needs to be banned? On paper, yes. However, there's one thing any powerful Pokemon has to do in order to actually do its damage; get on the field. And this is where Toxtricity can have problems. Its decidedly average Speed tier means that most teams will have 2-3 Pokemon, at worst, that outspeed Toxtricity and many offensive teams will have 4-5, at worst, that do the same. This is where Toxtricity can find itself struggling as it will sometimes be force to wait to come in until one of its teammate is KOed before it can shatter the ears of one of the opposing Pokemon.