>>45294317252+ Atk Choice Band Rillaboom Grassy Glide vs. 0 HP / 4 Def Blaziken in Grassy Terrain: 158-186 (52.4 - 61.7%) -- 98.8% chance to 2HKO after Grassy Terrain recovery
252+ Atk Choice Band Rillaboom Knock Off (97.5 BP) vs. 0 HP / 0 Def Dragonite: 176-208 (54.4 - 64.3%) -- guaranteed 2HKO
252+ Atk Choice Band Rillaboom Knock Off (97.5 BP) vs. 0 HP / 4 Def Salamence: 203-239 (61.3 - 72.2%) -- guaranteed 2HKO
-1 252+ Atk Choice Band Rillaboom Wood Hammer vs. 252 HP / 112+ Def Landorus-Therian in Grassy Terrain: 238-282 (62.3 - 73.8%) -- guaranteed 2HKO after Leftovers recovery
252+ Atk Choice Band Rillaboom Knock Off (97.5 BP) vs. 252 HP / 0 Def Heatran: 161-190 (41.7 - 49.2%) -- guaranteed 3HKO after Grassy Terrain recovery
252+ Atk Choice Band Rillaboom Knock Off (97.5 BP) vs. 0 HP / 0 Def Articuno-Galar: 388-458 (120.8 - 142.6%) -- guaranteed OHKO
252+ Atk Choice Band Rillaboom Grassy Glide vs. 0 HP / 0 Def Articuno-Galar in Grassy Terrain: 135-160 (42 - 49.8%) -- guaranteed 3HKO
252+ Atk Choice Band Rillaboom Knock Off (97.5 BP) vs. 252 HP / 184+ Def Zapdos: 144-170 (37.5 - 44.2%) -- guaranteed 3HKO
Don’r underestimate the best move in the game. Knock Off still does a shit ton of damage and it removes their items too, so it’s impossible for them to switch back in.
It’s why people would still use Rillaboom even if Tapu Bulu got Grassy Glide.