Thread:B214/@comment-30100337-20170615155045/@comment-30100337-20170615172054

I just went through all of the light novels and searched for the terms hundred, thousand, years, age, and old and only Issei has a concrete age and rosswiesse is given the age range of 17-18 years old when she becomes a devil. it is in volume 9 afterwords.

I might have missed something but that is what I found.