Choice Band Landorus-T
Landorus-Therian @ Choice Band
Ability: Intimidate
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Earthquake
- U-turn
- Rock Slide
- Superpower
Lando-T needs to be physical to pose an offensive threat without relying on super-effective coverage, and we slap a CB onto that for power levels exceeding those of Zygarde. Fortunately in this metagame, the only common Intimidate user is Incineroar, who can't safely switch in. Rillaboom is the bigger threat with Grassy Terrain, but it's a vulnerable U-turn target, with CB enabling a 2HKO. EQ immune mons other than Zapdos aren't common in this metagame, but usually EQ immune mons are weak to Rock Slide, with even defensive Zapdos always getting 2HKOed by Rock Slide. You can U-turn on Cress too.
252 Atk Choice Band Landorus-Therian U-turn vs. 248 HP / 36 Def Rillaboom: 260-308 (64.5 - 76.4%) -- guaranteed 2HKO after Grassy Terrain recovery
Rock Slide and Superpower also have good power and coverage under Grassy Terrain and if you don't want to hurt your teammate; these two moves + U-turn let Lando-T put in work even if EQ isn't clickable. FYI Heatran still gets OHKOed by CB EQ even in Terrain. I used to use bulkier spreads, but with the offensive metagame, I think Jolly is better to outspeed +Speed Rillaboom for the faster U-turn and Adamant Zygarde/Kyurem-B (120 HP Kyurem is always OHKOed by Superpower). You still have enough bulk to survive a Kartana crit Leaf Blade (outside Terrain) and only be 3HKOed by Band Zygarde Arrows and +124 Atk Seed Rilla Grassy Glide in Terrain with Intimidate.
You need more support than CB Zygarde, but it has the advantage of more power, Intimidate + a decent power U-turn, and better coverage. Defog Zapdos works well as an EQ-immune mon that clears Grassy Terrain and checks EQ-resistant Pokemon.