>>44981036Rillaboom doesn’t have to worry about Tapu Bulu. Rilla has to worry about Tapu Koko instead.
Rillaboom is so good because it’s the face of HO, like how Pelipper is the face of Rain HO.
U-turning into Hawlucha on a weakened team while something that can’t threaten it is a win condition that can’t be beat. It also has knock off to cripple walls, one of the strongest moves in Grassy Terrain boosted Woodhammer, a priority move stronger than Talonflame’s brave bird, and that Grassy Terrain can offset Life Orb damage so your attacking pivots can attack more.
Tapu Koko has that U-turn, but also has Rising Voltage, insane speed, Roost, and helps against Bulky Grasses like Amoongus/Tangrowth as it prevents Pokemon from sleeping. Tapu Koko can also just replace Zeraora on HO teams as well, freeing up a slot for another Pokemon.
