So my Slowpoke has the Own Tempo ability, but I'm wondering if it will change once it evolves? I really don't want it to change, so before I level it up anymore, I am wondering if it will change to Oblivious when it evolves or if it will stay as Own Tempo.
This is HG/SS.
It will stay as Own Tempo. Abilities only change if the evolved form has different abilities than the pre-evolved form. For example, Lillipup has the abilities Pickup and Vital Spirit, but Herdier has Intimidate and Sand Rush. So when it evolves, Lillipup's ability will change. But this doesn't happen for Slowpoke, because Slowbro (and Slowking) have the exact same abilities.