Rammus and his armor
Why is it that Rammus uses AP? His passive converts 25% of armor into attack damage and his W compliments this by returning 10% of his armor as magic damage when it is active. I feel as if Rammus has a handicap because none of his abilities use AD yet he gains AD based off of his armor. Could someone explain this to me please?
Edit - His E also lowers armor and not MR.