Venusaur-Mega @ Venusaurite
Ability: Thick Fat
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Leech Seed
- Giga Drain
- Sludge Bomb
- Synthesis
Mega Venusaur's typing and natural bulk means that it doesn't give a shit about what Tapu Bulu could do.
252+ Atk Choice Band Tapu Bulu Wood Hammer vs. 252 HP / 252+ Def Mega Venusaur in Grassy Terrain: 40-47 (21.3 - 25.1%) -- possible 5HKO after Grassy Terrain recovery
252+ Atk Choice Band Tapu Bulu Superpower vs. 252 HP / 252+ Def Mega Venusaur: 35-42 (18.7 - 22.4%) -- possible 6HKO after Grassy Terrain recovery
+2 252+ Atk Tapu Bulu Continental Crush (180 BP) vs. 252 HP / 252+ Def Mega Venusaur: 141-167 (75.4 - 89.3%) -- guaranteed 2HKO after Grassy Terrain recovery
While taking absolutely zero from any of Tapu Bulu's moves (asside from +2 Continental Crush, but Mega Venusaur still lives and can heal with Synthesis), Sludge Bomb is a guaranteed OHKO on all non-AV sets.
0 SpA Mega Venusaur Sludge Bomb vs. 252 HP / 0 SpD Tapu Bulu: 252-300 (142.3 - 169.4%) -- guaranteed OHKO
0 SpA Mega Venusaur Sludge Bomb vs. 252 HP / 4 SpD Assault Vest Tapu Bulu: 168-204 (94.9 - 115.2%) -- 75% chance to OHKO
In addition, Mega Venusaur can deal with some of Tapu Bulu's most common partners, being Heatran and Toxapex. Versus Hetran, Mega Venusaur can stall it out with Leech Seed and Synthesis.
0 SpA Heatran Magma Storm vs. 252 HP / 4 SpD Thick Fat Mega Venusaur: 62-74 (33.1 - 39.5%) -- 99.3% chance to 3HKO
252+ SpA Choice Specs Heatran Overheat vs. 252 HP / 4 SpD Thick Fat Mega Venusaur: 156-186 (83.4 - 99.4%) -- guaranteed 2HKO
For Toxapex, Mega Venusaur is immune to Toxic, resists Scald, and can stall with Leech Seed and chip away with Giga Drain.
0 SpA Toxapex Scald vs. 252 HP / 4 SpD Mega Venusaur: 12-15 (6.4 - 8%) -- possibly the worst move ever
0 SpA Mega Venusaur Giga Drain vs. 252 HP / 4 SpD Toxapex: 37-45 (23.5 - 28.6%) -- guaranteed 4HKO after Black Sludge recovery and Leech Seed damage
As a bonus, Mega Venusaur can also deal with non-Flyinium Z Celesteela, Chansey, and Alolan Muk, some other potential partners for Tapu Bulu.