Board Thread:Question and Answer/@comment-26488086-20150616023848/@comment-26488388-20150616032638

They are dropped at random, and possess standard drop rates (for example Aphrodite was an SR AW, so therefore she has the standard SR AW drop rate of 1-5%).

The only other way to obtain them is there is a possible reward of any of the old AW when you complete a WG.