Well at least the special seasons have had good formats, unlike the online competitions. I'm excited to see what
Theorymon will come up since he was good at this last gen, but i'll have a try:
Kangaskhan @ Kangaskhanite
Ability: Inner Focus
EVs: 252 Atk / 4 SpA / 252 Spe
Lonely Nature
- Double-Edge
- Power-Up Punch
- Sucker Punch
- Ice Beam
Normal is a sick offensive type now as nothing resists it. Need to watch out for Mega Gengar though as Shadow Ball will bop you and it now resists Sucker Punch. Ice Beam 2HKOes Avalugg which is always popular in inverse and counters Kang otherwise.
Serperior @ Focus Sash
Ability: Contrary
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Leaf Storm
- Glare
- Taunt
- Light Screen / Reflect / Mirror Coat / Synthesis / Hidden Power Fire
Grass is a much better offensive typing too, and Leaf Storm can pretty much sweep on its own. Back in ORAS this was used more defensively with Rocky Helmet and Reflect but I expect it to be more offensive this gen, possibly used often as a lead to get something in to set up safely. Lucky for all the people who've already bred HP Fire Serp for normal BSS, as it can now be used to hit the Water- and Rock-types that resist Leaf Storm
Porygon2 @ Eviolite
Ability: Trace / Download / Analytic
EVs: 244 HP / 252 Def / 12 SpD
Bold Nature
- Recover
- Tri Attack
- Shadow Ball
- Trick Room / Toxic / Foul Play
Dragons are overpowered in this format, so you have to use something that's bulky enough to live an unresisted hit. Porygon2 is the gold standard here
Glalie @ Leftovers
Ability: Moody
EVs: 172 HP / 84 SpD / 252 Spe
Timid Nature
- Protect
- Substitute
- Sheer Cold
- Frost Breath / Icy Wind
Glalie is way harder to take out now since Ice is now a respectable defensive typing. You can't snipe it with Mach Punch, Bullet Punch, or Vacuum Wave, and it resists Infiltrator Chandlure's Fire STAB. Ice types were made to be immune to Sheer Cold this gen and I'm not sure how that interacts with Inverse, I'm guessing they can be hit with it here, but if not you can just muscle through with super effective Frost Breath
Avalugg @ Rocky Helmet / Leftovers
Ability: Sturdy
EVs: 252 HP / 252 Def / 4 SpD
Impish Nature
- Avalanche
- Recover
- Mirror Coat
- Toxic / Roar
This was beastly in gen 6 with all the physical attackers. It might be a little worse with more special attackers this gen but it'll still be used quite a bit.
Dragonite @ Lum Berry / Choice Band / various Z moves
Ability: Multiscale
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Outrage
- Extreme Speed
- Dragon Dance / Fire Punch
- Roost / Earthquake
Dragon is only resisted by Dragon, so it's EXTREMELY potent in this, meaning any Dragon-type is deadly in this but I chose good old Dragonite. Garchomp, Hydriegon, even Outrage Mega Salamence will be great (which is why Porygon2 is better than usual here since you need something with enough bulk to live an un-resisted hit!).
Porygon-Z @ Normalium Z
Ability: Adaptability
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Tri Attack / Ice Beam / Dark Pulse / Thunderbolt
- Conversion
- Recover
- [coverage move]
This thing will be a menace if allowed to set up. Normal (Tri Attack) PZ will shine imo since normal-type moves are so good now, but there's merit in converting into something like Ice or Dark. Since you don't need 3 attacks in this format you can easily fit Recover there now.
Tapu Lele @ Choice Scarf / Choice Specs / anything really
Ability: Psychic Surge
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature
- Psychic
- Psyshock
- Moonblast
- filler?
There are no immunities in Inverse, and almost nothing resists Psychic-type moves. Those nooby "Lele+Zam/Metagross" teams from early gen 7 BSS will be unironically good here. I'm kinda tempted to try a lead Terrain Extender Lele set in all honesty lol.
Tapu Koko @ Choice Specs
Ability: Electric Surge
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Volt Switch
- Thunderbolt
- filler?
- U-turn?
Tapu Koko benefits from no immunities just like Lele does, and can spam Specs + Terrain boosted Volt Switches all day providing there isn't a Marowak / Thundurus-T / Electivire(lol) in the back.
Snorlax @ Iapapa Berry
Ability: Gluttony
EVs: 252 HP / 4 Atk / 252 SpD
Careful Nature
- Curse
- Recycle
- Return
- Facade
RestTalk Snorlax was surprisingly popular in Inverse last gen. With the buff to the FIWAM berries this gen, Gluttony Lax has been a legit threat in regular BSS, so I expect it to be a huge threat here. I have no idea if this will be the set to use, but since you can now drop Restalk for simply Recycle you can now run both Return and Facade and not worry about bad Sleep Talk turns.
That's about all I can think of off the top of my head for now.
Here's the stats for the season of Inverse during ORAS. This should be pretty valuable while this meta develops.