Unaware

Full effect

This Pokémon ignores other Pokémon's stat modifiers for the purposes of damage and accuracy calculation. Effectively, this affects modifiers of every stat except Speed. The power of Punishment and Stored Power is calculated as usual. When this Pokémon hurts itself in confusion, its stat modifiers affect damage as usual.

In game description

When attacking, the Pokémon ignores the target's stat changes.

Using Unaware in Cobblemon

Abilities are passive and always active, so Unaware 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.