Best core in all of OU

Mantine @ Leftovers
Ability: Water Absorb
Shiny: Yes
EVs: 252 HP / 4 Def / 252 SpD
Calm Nature
IVs: 0 Atk
- Scald
- Defog
- Roost
- Toxic
Buzzwole @ Leftovers
Ability: Beast Boost
EVs: 176 HP / 212 Atk / 56 SpD / 64 Spe
Adamant Nature
- Substitute
- Focus Punch
- Leech Life
- Earthquake
Excadrill @ Leftovers
Ability: Mold Breaker
EVs: 252 HP / 200 SpD / 56 Spe
Careful Nature
- Stealth Rock
- Iron Head
- Earthquake
- Rapid Spin