Volcarona

Volcarona is the only Bug / Fire type Pokemon in 1v1, which helps it deal with the abundance of Psychic-, Fairy-, and Steel-types in the metagame like Mega Slowbro, Tapu Lele, Mega Gardevoir, and Mega Metagross. Its good Special Attack and Speed along with Quiver Dance give it the potential to outspeed most other Pokemon after one boost, such as non-Hidden Power Rock Naganadel. With Substitute, Volcarona can bring its HP under one third and unleash a devastating Swarm-boosted Savage Spin-Out. This move can overwhelm the majority of Pokemon that do not resist it, letting Volcarona deal with most Pokemon that are slower than it. Unfortunately, Volcarona's Bug / Fire typing is poorly equipped to fight extremely prevalent Flying- and Water-types like Dragonite, Greninja, Tapu Fini, and especially Rock-types and Rock-type move users like Crustle and Donphan. Despite excellent offensive stats, Volcarona has subpar defensive stats, and heavy investment is required to take even some neutral hits, such as Fake Out followed by Giga Impact from Mega Lopunny and Hyper Beam from Choice Scarf Porygon-Z.