Supreme Overlord
Attack and Special Attack are boosted for each party Pokémon that has been defeated.
Full effect
When the Pokémon enters a battle, its Attack and Sp. Atk stats are slightly boosted for each of the allies in its party that have already been defeated.
In game description
When the Pokémon enters a battle, its Attack and Sp. Atk stats are slightly boosted for each of the allies in its party that have already been defeated.
Pokemon with Supreme Overlord
Using Supreme Overlord in Cobblemon
Abilities are passive and always active, so Supreme Overlord costs you nothing to run. If it is marked hidden on a species above, expect it to be harder to obtain: servers differ in whether hidden abilities come from breeding, an Ability Patch, or events.
See the Pokedex for which abilities each species can have, and IVs, EVs and breeding for how to actually pass one down.