I'd like to make an extensive post about what I firmly believe is the single best support mon in the entire game, and a top 5-10 mon in the entire metagame altogether:
Galarian Slowking. I think that it's pretty widely accepted to be a fantastic mon, but I think that it's the ultimate support mon in this relatively fresh metagame and that it deserves some serious time in the spotlight.
What does Galarian Slowking do?
Glowking's got a
lot going for it, but it's generally accepted to be a hard-hitting defensive pivot that provides a ton of defensive utility and offensive pressure at the same time. It's got a good typing, fantastic bulk, solid Special Attack, an amazing movepool, Regenerator, and the immense power of STAB Future Sight alongside Slowking's signature move, Chilly Reception. More on Chilly Reception later; this move is a fucking
gamechanger.
That being said, it's more than
just one of the best pivots in the game. It was already a top threat in SS OU by doing that with its classic Assault Vest set, but in this metagame a lot has changed.
What changed for Galarian Slowking?
The tier prior to HOME had a gross lack of strong Psychic-types. The best you'd end up seeing were Hatterene and the occasional Indeedee+Armarouge PsySpam core, and Slowking had its place but wasn't super splashable. Glowking faces basically no competition, from anything prior to HOME or anything new or returning alongside it, in the role it fills besides its Kantonian cousin. What
did come with it, though, was a massive influx of powerful Fighting-types, ranging from both Zamazenta formes to Sneasler to Urshifu-R, and other strong wallbreakers like Enamorus-Incarnate and Ursaluna, that all benefit from some part of Glowking's wide support movepool. Of course, mons like Chien-Pao, Great Tusk, Kingambit, and the like
also really like its support, but still. The Future Sight+Wallbreaker core was a prominent part of SS OU ever since Urshifu-S tore the metagame a new one, and it stayed prominent even after it was banned through Urshifu-R, Weavile, and the like.
That being said, Glowking got access to a move that completely alters how it plays the game:
CHILLY RECEPTION. This move sets Snow and pivots Glowking out, and with it very much living up to the "SLOW" in its name, this mon went from becoming a powerful offensive pivot to becoming one of the best offensive pivots ever. Now, this isn't a completely new move; its Kantonian cousin had this move all generation, and used it to great effect alongside mons like Baxcalibur. But in regular Slowking's case, this move simply replaced the Teleport that had been removed from its movepool going into Gen 9;
Glowking, however, never got Teleport last generation. Getting that slow switch move changes everything, since Glowking can use its bulk, typing, Regenerator, and ability to force switches to get a free slow Chilly Reception off and bring something in.
That's
still not everything, though; Glowking has also gained access to Terastallization like everything else, and it can utilize the mechanic extremely well as far as support mons go, and if it wants to go on the offensive it can still take advantage of the mechanic very nicely. Moreover, Trick Room has proven itself to be a viable strategy for the first time in a very long time thanks to the infamous Cocaine Bear, Ursaluna, and with Magearna's recent quickban (good) Glowking is finding itself in a prime position to set up Trick Room and get this absolute behemoth of a mon in safely, guaranteeing it gets statused and giving it an opportunity to obliterate an entire team with OHKO after OHKO.
What does Galarian Slowking support?
If it hits hard but needs to preserve its HP and thus can't directly switch into an attack, Glowking facilitates (or even enables) it. Here are a few examples:

all of these Fighting-types
really like Glowking's strong Future Sight, as well as the obvious abillity for it to pivot them in with Chilly Reception. A STAB Close Combat, Surging Strikes, or boosted Body Press is already very strong, but with Future Sight support these moves' few drawbacks are largely mitigated. A Toxapex aiming to switch into a Fighting-type move risks getting obliterated by the Future Sight, and a Dark-type sponging the Future Sight gets OHKOed by a Close Combat or Body Press.

They're bulky, they hit hard, but they're incredibly slow. Now, both are phenomenal mons as is despite their Speed, but both appreciate Glowking's Future Sight support letting them wallbreak more easily. If it opts to run Trick Room as support, these two become powerful sweepers even against fast threats that could outspeed them, live a Kingambit Sucker Punch, and possibly OHKO them. Ursaluna can become a lategame cleaner and an early-game wallbreaker all the same.

Other Regenerator mons like the slow switches provided by Glowking, and they can form a core that can be quite difficult to break past.
What sets can Galarian Slowking pull off?
The short answer? A lot. But with how customizable it is, there's a little bit of a longer answer here, too:
Slowking-Galar @ Heavy-Duty Boots / Shuca Berry
Ability: Regenerator
Tera Type: Fairy / Flying
EVs: 252 HP / 252 Def / 4 SpD
Relaxed Nature
IVs: 0 Atk
- Future Sight
- Chilly Reception
- Sludge Bomb
- Ice Beam / Slack Off
Shoutouts to Alkazoth in the OU Discord for sharing this second one with me!
Slowking-Galar @ Heavy-Duty Boots / Shuca Berry / Colbur Berry
Ability: Regenerator
Tera Type: Dark
EVs: 252 HP / 16 Def / 240 SpD
Sassy Nature
IVs: 0 Atk / 21 Spe
- Future Sight
- Chilly Reception
- Surf / Slack Off
- Sludge Bomb
So here are two potential Chilly Reception sets. They're good; they do what they need to do, and sometimes they can pull off a lot more. That said, you can mess around with these IVs in quite a few ways; sometimes you just want to outpace Clodsire, sometimes you want to just outslow a max-Speed Glowking, and sometimes you want to go as slow as humanly possible to get the slowest Chilly Reception possible.
Slowking-Galar @ Shuca Berry / Colbur Berry / Mental Herb
Ability: Regenerator
Tera Type: Dark / Flying
EVs: 252 HP / 4 Def / 252 SpD
Sassy Nature
IVs: 0 Atk / 0 Spe
- Trick Room
- Chilly Reception
- Slack Off
- Sludge Bomb / Psyshock / Future Sight
The Trick Room setter, which can facilitate a Kingambit or Ursaluna sweep with ease.
Slowking-Galar @ Heavy-Duty Boots
Ability: Regenerator
Tera Type: Flying / Fairy
EVs: 212 HP / 252 SpA / 44 Spe
Modest Nature
IVs: 0 Atk
- Nasty Plot
- Psychic / Sludge Bomb
- Surf / Ice Beam
- Flamethrower / Slack Off
If you want Glowking to go on the offensive, here's a possible option! Tera Flying allows it to set up on Great Tusk, and then it can utilize its absurd coverage and great power after a boost to break past a team's defensive backbone. This is an underrated set that I firmly believe is worth exploring.
Slowking-Galar @ Black Sludge
Ability: Regenerator
Tera Type: Fairy / Dark / Flying
EVs: 212 HP / 252 SpA / 44 Spe
Modest Nature
IVs: 0 Atk
- Trick
- Slack Off / Flamethrower
- Psychic
- Sludge Bomb / Ice Beam
Or you could run Trick+Black Sludge and cripple something with a bunch of free passive damage. Mons that rely on their items for longevity HATE this!
Slowking-Galar @ Assault Vest
Ability: Regenerator
EVs: 252 HP / 12 Def / 124 SpA / 120 SpD
Calm / Sassy Nature
- Future Sight / Psychic
- Sludge Bomb
- Flamethrower
- Scald / Ice Beam / Earthquake
Or you could go back to basics, with the classic Assault Vest+Future Sight set! This is the best check to special Iron Valiant we've ever gotten, and even Earth Power Enamorus doesn't have the easiest time beating it; hell, even physical Iron Valiant sets kinda rely on Knock Off to beat it. I think the Chilly Reception sets are overall the better ones, but this set is the epitome of what Glowking has always been about and is still a blast to use in my experience.
Conclusion:
Galarian Slowking is a mon that is respected by many at this point, but I think it's outright one of the best mons in the tier and will only improve as time goes on. The Chilly Reception sets are gamechangers for the metagame's landscape, make no mistake, but I think this mon is so incredibly customizable that you could pull off a lot of different things with it, and pull them all off very well.
So go on; use Galarian Slowking more! There's so much room for experimentation with this mon, and the support it provides is unrivalled. I'd easily argue that this is one of the best glues in the entire tier.