
This is the team’s main water resist, being a check to Urshifu-R, SD Gliscor, Ogerpon-W, and even Ursaluna on some occasions. It does this somewhat okishly due to stun spore threatening a large majority of Pokémon that would want to come in on Sinistcha like Heatran and Mchary. It also does fine against a majority of rain sweepers like mswamp and Barra especially with stun spore threatening switchins those teams have like tornadus-T and Archaludon. Super boosted Hexes also deal considerable damage to Pokemon statused, like Gliscor and Galarian Slowking. Tera Poison keeps the fighting resist while also gaining a new one to fairy, allowing it to use stun spore against iron valiant in a pinch, and a toxic immunity which is useful in pivoting around Alomomola.

Very self explanatory, main ground on the team and provides fog so Koko, heatran, and Mmedi can stay around longer. Team didn’t feel overly offensive, more of a BO type team, so I thought defog was fine on this structure. Taunt makes sure stuff like Ferro can’t leech you or even denies hazards from other stuff like opposing Landorus-T and Gliscor, which although defog removes said hazards those Pokémon can still threaten Lando with toxic. Rhelm is used so Mlop and Mmedi just doesn’t click a million times against this and makes them much easier to play around. Tera fairy is also an option to make Darkrai easier to play around

Stun spore sinistcha has one huge flaw; it struggles immensely with Steel types like Heatran and especially Ferrothorn (with the latter being immune to stun spore). Mmedi solves this issue, and makes playing around those steels much easier along with having good synergy with sinistcha. Sinistcha paralyzes certain foes so Mmedi clicks easier, while Mmedi is the anti steel for this team so sinis doesn’t worry as much. Mmedi also improves how the team makes progress vs. fat / balance teams featuring Toxapex and the aforementioned Ferrothorn. Otherwise it’s pretty simple stuff.

This is the team’s speed control and is also valuable for destroying the flying types sinistcha hates, like Tornadus-T and
Zapdos. Not only that, it’s the team’s main way of revenge killing Ogerpon-W and Darkrai as well, the latter of which Sinistcha hates. U turn also brings in the main progress makers, Mmedi and hydrei, in safely.

We needed the obligatory steel and fire resist; Sinistcha can only do so much against fire types like Volcarona and MYard. It also brings the main fairy and psychic resists, useful for playing around Tapu lele and iron valiant easier (remember, because Sinistcha is ghost type, iron valiant is deterred from using focus blast lest they get punished by stun spore). Besides that it also clicks stealth rock and makes bolt and koko much easier to play around. Not much else that is special

Now we get to the real heat. I wanted some way to exploit the landocrown offenses that had been popping up recently (and the ones sinistcha got overwhelmed by too quickly), so I wanted some dark type. I thought weavile was a no go since it was rocks weak and made Ferrothorn much more of a nuisance. Darkrai was an option, but I found Darkrai gets very few opportunities to come into a game based on its typing alone. Hydreigon fit what I wanted perfectly. It has u turn, a distinct trait from Darkrai, which makes playing around checks to hydreigon like spdef Heatran and Mega Tyranitar much easier to do and allows Mmedi to come in against them and force progress, which then makes sinistcha’s job easier to do. Not only that, Hydreigon also gives the team a way to threaten landocrown offenses (which is made easier with hydrei due to its ground immunity + volt switch resistance). Hydreigon also has useful typing in some scenarios where it can end up threatening raging bolt (with its tclap resist) or trade agaisnt something like Mega Charizard y.