It already knows Return, aerial ace, earthquake and I was wondering shouldd I pick brick break or hammer arm???
I would go with Brick Break because you can shatter Reflect/Light screen and you don't get a Speed decrease. Also you have more accuracy. But in my opinion, I would pick Shadow Claw because then you can cause major Damage on Ghost types. But if not, go with Brick Break.
I would go with shadow claw because it whould cover that weakness.
Sooo Brick break.