[REQUEST] Last party member

[P35]

Hey guys! So I've been going through super singles in the battle tree and I need a third member of my team (I have a Golisopod as a place holder right now and he's doing next to nothing) here's my totally creative and not overused team (I'm to to competitive battling ok)
M-Salamence 
252 Attack 252 Speed 4 Hp
Return 
Earthquake 
Roost
Dragon Dance

Toxapex-Black Sludge
252 Hp 252 Defense 4 Speed
Recover
Toxic 
Scald
Haze
(Special Thanks to the to people that helped me out on how I should run Toxapex)

Id appreciate any suggestions on what Pokémon, ev spread, and movesets I should use. Also feel free to leave some suggestions regarding Salamence and Toxapex

[Spyro190]

First of all I want to put before that playing vs AI isn't competitive battling. Anyway I undestand: that's the only section suitable for this 3d, so it's ok.
What makes Battle Tree so fun (I'm absolutely ironic, you know) is that you just need to win as fast as possible: you should stop using slow strategies like Toxic/Scald's stall, so stop using Toxapex. But if you like it so much is your business.
Great patners for MSalamence without Fire coverage are pokèmon capable of owning threats immune to Ground with a resistance to Flying, such as Levitate Bronzong and Skarmory. Volcarona with its Fire STABs does it perfectly; it is also one of the strongest setup sweeper, so it's perfect for Battle Tree.

Praise the Sun (Volcarona) (F) @ Firium Z/Psychium Z/Life Orb 
Ability: Flame Body  
EVs: 4 Def / 252 SpA / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Quiver Dance  
- Fire Blast/Fiery Dance  
- Giga Drain  
- Hidden Power [Ground]/Hidden Power [Rock]/Hidden Power [Ice]/Psychic/Bug Buzz

Fire Blast+Firium Z should be used quiet always, but if you prefer Psychic in the fourth slot you need Psychium to hit harder and Fiery Dance suddenly becames the best Fire STAB. HP Rock and Ground hit Fire types, HP Ice hits Dragons. Life Orb and Bug Buzz are terrible options, but they exist.
Both Volcarona and MSalamence without Outrage/DClaw are scared by Garchomp: what about using Tapu Bulu/faster mons capable of OHKOing it instead of Toxapex? They also share a Rock weakness, so a Fighting type should be another nice choice.

[P35]

What i meant by competitive battling is that theres actually strategies and predicting and im pretty new to all that and i dont know the best sets/what i should run. But anyway thanks for the suggestion