1.

Cresceidon can survive 2 Tera Water Hydro Steams from full and threatens back with Thunder Wave and/or Moonblast. In general, Sun has difficulty switching in on the combination of Thunder Wave and Moonblast.
This team can use SpDef Corv as a pivot, U-turning to break Multiscale and bring in Malaconda for free (which can then threaten Glare/Knock Off or Parting Shot). Additionally, Roaring Moon can take advantage of Lum Berry and Tera Ground to set up on Cresceidon.
2.

Sun wants to spam dragons, so it's inevitably weak to Hemogoblin (it doesn't help that the best support pieces, Great Tusk and Malaconda, also lose to Hemogoblin).
On this team, we use Iron Moth and Tera Fire Great Tusk to check Hemogoblin. Notably, Great Tusk runs Rocky Helmet + Taunt to deny Hemogoblin the opportunity to set up, or take advantage of Sun to recover 2/3 HP with Moonlight. Boots Moth helps with the issue of taking 25% from Rocks switching in on Hemo, and possibly burning Booster if Moth is holding it.
3.

Gliscor with Protect can scout the moves of our Choiced breakers. Most notably Spikes variants are very annoying for Sun, since Spikes provide constant chip on Wake and Malaconda, and Glisc easily harasses spinner Tusk/Malaconda with Toxic and EQ chip.
On this team, Roaring Moon can take advantage of Gliscor's Protect/Toxic to set up multiple Dragon Dances and sweep. Additionally, Corviknight has a solid MU into Spikes Gliscor, and a very good MU into Spikes Arghonaut.
4.

Slowking-Galar can pivot in on Walking Wake and click Chilly Reception, resetting the Sun and removing a lot of momentum from the Sun team.
On this team, Roaring Moon can take advantage of Slowking Galar's Thunder Wave by terastallizing to set up multiple Dragon Dances and sweep.
5.

Garganacl with Protect can scout the moves of our Choiced breakers. Additionally, Tera Water can annoy Walking Wake greatly, and Sun has difficulty switching in to Salt Cure.
Previously, I have tried Covert Cloak offensive Tusk as a Garg answer (solid option) but here we use Tera Ground Moon with Roost to abuse Garg (a very committal answer, but sometimes you can force a win or major progress immediately). If opponent also has Argh, you might be doomed (perhaps Corv can be Cloak or something).
6.

Bad MU all around, good luck... Maybe SpDef Corv saves you here.
Can try 252+ Atk/80Def/176Spe on Moon to outspeed Kyurem. Otherwise, just outplay...
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