User blog comment:B214/Question and Answers 2/@comment-82.178.34.99-20140206195350/@comment-3965848-20140206223333

One way of getting additional wings would be geneticly, there is a chance that Akeno got multiple wings due to her father having 10 wings, like how Vali had 4 pairs of Devil wings due to being the Great-Grandson of the original Lucifer.

Although I'd like to think that it's a possibility for any Devil, Fallen Angle and Angle to obtain more sets of wings.