I found Echomask's suffix,
-mask, on an online warrior cats generator. It was never intended to reflect her personality. I thought it sounded cool so that's why I used it. Then when people commented on her name I realized "Holy...this suffix actually completely shows her personality...but secretly!" So I just kinda went along with "Oh yeah, it was intentional, blah blah blah" but it never was. :) Thank the generator for that one.