Typhlosion ♂ (Fire) @ Choice Scarf

Trait: Flash Fire
EVs: 4 Def / 252 SAtk / 252 Spd
Modest Nature (+SAtk, -Atk)
- Eruption
- Solar Beam
- Lava Plume
- Hidden Power [Rock]
Jolteon ♀ (Electric) @ Choice Specs

Trait: Volt Absorb
EVs: 4 HP / 252 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
- Volt Change
- Shadow Ball
- Signal Beam
- Hidden Power [Ground]
Arcanine ♂ (Fire) @ Heat Rock

Trait: Intimidate
EVs: 252 Atk/252 Spd/4 HP
Adamant Nature (+Atk, -SAtk)
- Flare Blitz
- Close Combat
- Extreme Speed
- Wild Charge / Crunch
Slowbro ♂ (Psychic, Water) @ Leftovers

Trait: Regeneration
EVs: 116 HP / 176 Def / 216 SDef
Modest Nature (+SAtk, -Atk)
- Calm Mind
- Boil Over
- Psycho Shock
- Fire Blast
Pidgeot ♂ (Normal, Flying) @ King's Rock

Trait: Tangled Feet
EVs: 252 Atk / 4 Def / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Brave Bird
- Frustration
- U-turn
- Steel Wing
Lapras ♀ (Water, Ice) @ Leftovers

Trait: Water Absorb
EVs: 252 Atk / 4 Def / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Dragon Dance
- Waterfall
- Ice Shard
- Level Field
I would also love to incorporate Gengar into my team, but with whom to swap him with is my concern.
In my game, this team is pretty stable and steady, though at times we encounter a few bumpy battles—if there are any fixable flaws, please don't hesitate to tell me!
Critiques are totally fine!