Calm Mind. Definitely Calm Mind.
Calm Mind raises the user's Special Attack and Special Defense by one stage each.
-- Pokemon DB on Calm Mind
Role Play copies the opponent's ability, replacing its own with that of the target's.
-- Pokemon DB on Role Play
Calm Mind will increase both Sp Attack, and Special Defense, so you can hit harder. Most of the Pokemon you battle do not have any good abilities that are useful, forget great. Competitive play maybe Calm Mind, but a Specs is better, because Alakazam/ Kadabra just don't have proper defenses to set up.
Please put the rest of your team/ moveset, so I can help you better.