Necrozma-Dusk Mane @ Ultranecrozium Z
Ability: Prism Armor
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Photon Geyser
- Earthquake
- Outrage
Kyogre @ Blue Orb
Ability: Drizzle
EVs: 4 Def / 252 SpA / 252 Spe
Modest Nature
- Water Spout
- Calm Mind
- Origin Pulse
- Ice Beam
Generally stall teams have some form of out vs most breakers meaning there's more to breaking a stall(ish) team than sticking 2 mons with good matchups - you have to pilot the matchup properly. Wallbreakers and sweepers like these 2 don't have longevity which means mistakes are extremely costly.
For this team though I think Ultra and Kyogre put out way too much pressure. Only Sableye is any use against SD Ultra sets due to Ho-Oh's offensive set... without recovery to make it scarier. I think pretty much any Ultra variant will give this team insane pressure because of its Speed and potential coverage options - and there's no real way to kill it or even scout it before it does something deadly.
Kyogre just goes ham. There are 6 pokemon here that can't stand up to it and Groudon is special to really throw this matchup to the wolves. Only Arceus-Ground outspeeds it and that isn't any help. Best case scenario is that Kyogre makes a misplay and doesn't come in safely, which is what I refer to in the first paragraph.
Combine these two and this team is always on the back foot with little hope - they have full control of the game and its a case of them losing, not you winning. The usage of these two mons (and these sets in particular) is too high to try and ignore.