Incinerator

V-create has always been the premier source of near-unconditional, non-choiced initial power in BH. Unfortunately as a result some people have figured out that running a Fur Coat Fire resist is pretty good, so here is V-create but special.

252+ SpA Life Orb Sheer Force Iron Moth Blue Flare vs. 252 HP / 252 SpD Arceus-Ghost in Sun: 437-515 (98.4 - 115.9%) -- 87.5% chance to OHKO

This is what Iron Moth does. This is the reason to use Iron Moth.

Wildbolt can miss, Electro Drift hits Helmet and inflicts LO chip, and Thunderbolt is lower power. Typically you want to hit Water-types and Fire-immune Celesteela, but if you aren't concerned with those things then Sludge Wave can also be used.

Here we have Sticky Web so Iron Moth can set its own hazards, but it isn't a fan of stuff like Bounce Eternatus or Knock/Mortal Koraidon, so it might be best to leave the webs to a teammate and run a different third instead. Or you could run double Webs, that also works.

Earth Power deals about 60% to Eviolite Imposter; it's possible to up this to at maximum 93% through decreased SpDef investment, but this leaves you very specially frail. Sun Blue Flare deals about 25% to Eviolite Imposter. Earth Power provides the best all-around coverage into WBB Steels and stuff like Nihilego, but if you're using Pain Split (which also recovers on non-Imposter Chansey/Blissey), it makes more sense to not run any anti-Imposter attack so you can Split on them. Focus Blast can beat WBB Steelceus, but has very limited use in general. Magic Powder or even something like Soak or Forest's Curse can be used to force out resists, leaving Iron Moth free to roam.

-trollkastel seal of approval

Run sun, speed control such as Webs, and some form of imposter-proofing and you're set. Hazard removal is appreciated but optional. You 2HKO all non-resistant RegenVests except for Blissey, and those turn into OHKOs with Vests removed. This isn't a perfect wallbreaker, but it's about as close as you can get without getting into the territory of mons who can't do anything without hitting predictions.

Running Eject Button on a teammate is recommended to skip the queue and get Iron Moth in as quickly as possible.

SpDef Giratina and Scales resists beat you and there isn't much you can do about this. RegenVest Blissey avoids the 2HKO, WBB Flutter walls you but struggles to actually do anything in return, WBB Earth Plate Steelceus can switch in and force you out, RegenVest Kyogre is a headache, Boots Koraidon/Eternatus are annoying, Garchomp lives one unless you're Ice Beam. Imposter is probably the most actually threatening thing because it tests your own team's sustainability. Lot of mons here, but they aren't autolosses by any means. You're using sun, you should have ways around passive play.