>>53737215In sunny weather, anything on par with lvl. 40 Chandelure, Darmanitan and I guess now Volcarona will be strong enough. The Emboar, Charizard and Blaziken are the only viable Blast Burn Pokemon at lvl. 40. Fire-type legendaries and megas will make it easier/more consistent, but Fusion Flare Reshiram is the only legendary viable at lvl. 30, with Moltres and Entei being borderline viable at lvl. 35.
In non-sunny weather, you're gonna need some variation of fire-type shadow legendaries, Apex Ho-Oh, Fusion Flare Reshiram and/or a fire-type mega, all at least at lvl. 40.