Actually, I think it will be a great offensive pokemon. Grassy Terrain Stab Choice Band Wood Hammer would ruin lives.
>252 Atk Choice Band Tapu Bulu Wood Hammer vs. 0 HP / 0 Def Mew in Grassy Terrain: 415-490 (121.7 - 143.6%) -- guaranteed OHKO
>252+ Atk Choice Band Teravolt Kyurem-B Outrage vs. 0 HP / 0 Def Mew: 394-465 (115.5 - 136.3%) -- guaranteed OHKO
This is assuming it has 120 base attack which seems kind of reasonable. It will make a great answer to most of the ground types in OU, especially since Grassy Terrain weakens Earthquake, letting it switch in on Landorus-T, Garchomp, etc. Lando-T might even start running Sludge Wave as tech for this thing. Defensively I'm less sure of how good it will be. Grassy Terrain gives it extra healing but it does the same to the opponent, and it has to compete with other grass types like Ferrothorn who has less weaknesses and more utility, Mega Venusaur who will probably be bulkier, Amoonguss who is a better pivot, etc. As a Grass/Fairy type, it presumably gets competition from Whimsicott and Morelull's evolution too. I think offensively it will shine and be able to distinguish itself, though.
