Rillaboom
Grassy Surge and Grassy Glide is an insanely strong combo. STAB Grassy Terrain Boosted 70 Power Priority from a high attack Pokémon is kinda awesome. It revenge kills many threats, deals a good chunk of damage to just about anything, and can be further boosted by a Swords Dance or a Choice Band.
Flying, Bug, and Fire types
B O O T S. Anything that returned that was weak to the rocks and saw that they could put on some boots rejoiced. Articuno, Moltres, Ho-Oh, Volcarona, Charizard, Lugia, and Dragonite rocked those boots the best, as they suffered quite a lot from those rocks.
Garchomp
He’s back, and he learned how to shoot scales. This raises his speed, and paired with a swords dance, makes him a monster.
Hatterene and Indeedee
A hated pair in Doubles, Indeedee often uses Follow Me and Hatterene uses Trick Room. Both of them can start using Expanding Force, a devastatingly strong move under the influence of Indeedee’s psychic terrain. It hits both opponents in doubles, gets STAB, and gets a ton of power in Psychic Terrain.
Barraskewda
As you mentioned, it can pivot now.
Weavile
Triple Axel is pretty nice. High power is something that’s very nice on a Pokémon that can’t do much on defense, and has great attack and speed. It’s a STAB move, and it’s got 120 power.
Physical Poltergeist Users
A very strong move with not too bad of a downside, as most opponents hold items. 110 power is pretty great! Marshadow, Dhelmise, Decidueye, and Golurk are a few examples.
Zapdos
As well as having some nice boots to wear, it now has Hurricane. This, paired with Thunder and Weather ball, makes it a very good attacker under the support of Rain.
Tornadus
Another Pokémon that really likes it’s new boots, it also got Nasty Plot. Paired with it’s high speed, a SpA boost can make it a really great attacker.
