(Always assume first item in the /'s is what I'd recommend, minus Blaziken's item depending on what you'd like to test)

Blaziken @ Life Orb / Blazikenite
Ability: Speed Boost
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- High Jump Kick
- Blaze Kick / Flare Blitz
- Knock Off
- Protect

Charizard-Mega-Y @ Charizardite Y
Ability: Drought
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Fire Blast
- Solar Beam
- Defog
- Focus Blast

Fletchinder
Ability: Gale Wings
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Acrobatics
- Swords Dance
- Tailwind / Wil-O-Wisp
- Roost

Victini @ Assault Vest / Choice Scarf
Ability: Victory Star
EVs: 224 HP / 252 SpA / 4 SpD / 28 Spe  OR 252 SpA / 4 SpD / 252 Spe
Modest Nature / Timid Nature
- Blue Flare
- Glaciate
- Energy Ball
- U-turn

Volcarona @ Lum Berry
Ability: Flame Body
EVs: 248 HP / 212 Def / 32 SpA / 16 Spe
Bold Nature
- Quiver Dance
- Fiery Dance
- Giga Drain
- Hidden Power [Ground]

Entei @ Choice Band
Ability: Pressure
Shiny: Yes
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Sacred Fire
- Extreme Speed
- Bulldoze
- Stone Edge

Additional Options:

Ninetales @ Life Orb
Ability: Drought
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Fire Blast
- Solar Beam
- Extrasensory
- Calm Mind / Pain Split / Substitute

(^ Over Char Y)

Darmanitan @ Choice Scarf
Ability: Sheer Force
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Flare Blitz
- Earthquake
- Rock Slide
- U-turn

(^ Over Entei)

Rotom-Heat @ Choice Scarf / Choice Specs
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature / Modest Nature
- Overheat
- Volt Switch
- Hidden Power [Ice]
- Thunderbolt

(^ Over Volcarona)