Viktor Q

I'm assuming this is a common question, but after hitting Q, your next auto attack does bonus magic damage. I am assuming this AA is using AD like a normal AA and is just being boosted by magic damage, but because it augments the attack animation completely, I wondered if it just doesn't count as a completely AP based spell with no AD like an auto attack.

I'm asking because with the frequency of me using Q+AA, I want to start taking Hybrid Pen runes because the reduced Magic pen is insignificant if the armor pen is being used. If not, I'll go back to magic pen.