Grass / Fighting: 59 / 241 / 141 / 59 / 31 / 139
Kartana @ Lopunnite
Ability: Beast Boost (-> Scrappy)
EVs: 252 Atk / 4 Def / 252 Spe
Jolly / Adamant Nature
- Swords Dance
- Leaf Blade
- Sacred Sword
- Psycho Cut
no
And by "no" I don't mean "help us all," I actually mean, no, this probably won't be as good as it looks, unfortunately. Kartana might be the initial Gen 7 mon you'd think to slap Lopunnite on for obvious reasons, but unfortunately it's still shut down by Zapdos, and outsped and OHKOd by mons like Absolite Manaphy and Glalitite Weavile. It also doesn't 2HKO Pdon despite 241 base Attack (which I know isn't easy, but still).
The other two Gen 7 mons that could viably use Lopunnite are Tapu Bulu and Buzzwole. SD dual stab Stone Edge Tapu Bulu is a menacing wallbreaker and provides Grassy Terrain support before you evolve it, and Buzzwole is in a similar boat. However, I don't think either of these are going to end up being meta staples. They're still pretty slow and their best Fighting stab lowers their Attack. Although they are pretty bulky on the physical side, the unfortunate side effect of Lopunnite is an additional weakness to Flying-speed (and Fairy, when Altarianite drops). Lopunnite Marshadow is good, but Lucarionite Marshadow is better so that's irrelevant.
Looking bleak in terms of new Gardevoirite users. The main problem is that it doesn't add Fairy type (so no, Gardevoirite Swellow or Flygon are both bad since neither of them are Fairy type), so I really don't think there are any viable Gen 7 users of it. Primarina is the only possible thing but it's not much stronger than Sylveon and still pretty slow and physically frail, so I wouldn't even consider that a viable option.
And Galladite is mostly inferior to other options. So basically, Lopunnite Kartana and Tapu Bulu are likely viable options, but not amazing.