Venusaur-Mega @ Venusaurite
Ability: Thick Fat
EVs: 232 HP / 252 SpA / 4 SpD / 20 Spe
Modest Nature
IVs: 0 Atk, HP,Def,SpAtt,SpDef
- Giga Drain
- Sludge Bomb
- Hidden Power [Fire]
- Synthesis

Gigalith @ Custap Berry
Ability: Sturdy
Impish Nature
- Sandstorm
- Stealth Rock
- Stone Edge
- Explosion

Tyranitar @ Focus Sash
Ability: Sand Stream
EVs: 252 Atk / 4 SpD / 252 Spe
IVs: HP,Att,Def,Speed
Adamant Nature
- Dragon Dance
- Fire Punch
- Stone Edge
- Crunch

Aerodactyl @ Life Orb
Ability: Rock Head
EVs: 252 Atk / 4 SpD / 252 Spe
IVS: HP,Att,Def,Speed
Jolly Nature
- Stone Edge
- Roost
- Earthquake
- Double-Edge

Serperior @ Leftovers
Ability: Contrary
Shiny: Yes
EVs: 56 HP/ 200 SpA / 252 Spe
Timid Nature
IVs: 0 Atk, HP,SpAtt,SpDef, Speed (I think SpAtt and Speed need to be 30 for HP fire?)
- Leaf Storm
- Hidden Power [Fire]
- Dragon Pulse
- Substitute

Whimsicott @ Focus Sash
Ability: Prankster
Timid Nature
- Stun Spore
- Leech Seed
- Endeavor
- Moonblast