Both Sherazard and Beramode have the same voice actress. The voice for Beramode is just more lower pitched. In my opinion, the the actor who was casted is perfect. She has a soft, warm, mature, weak and gentle voice that breaks/cracks easily, making you think of a very fragile person.
The voice actor's name is Yun So-Ra (윤소라). She's been the voice actor in 4 different shows: SBS cyber formula as 'Mickey', Tooniverse's Cat's Eye, MBC's Gundam 0083 as 'Nina Purpleton', Tooniverse's X File Detective as 'Goahla'. Most of the WOG3 cast was actually from Tooniverse.
Korean TV has a huge amount of of dubs and often multiple dubs of the same shows/movies/anime because of the nature of the Networks. So it's not uncommon for an actor to have a huge amount of roles and experience. I find it quite interesting that a voice like hers be in a 0083 dub and as Nina "my gundams are more important than your life" Purpleton!
As Sherazard/Beramode, the actress uses a unique way of speaking. If you are used to hearing Korean like I am, you would notice it right away. Korean language usually has a more "rough" sound to it, but when Sherazard/Beramode speaks, it's smooth and has little interruptions.
The actress is softening her consonants, almost whispering on them. In effect, she's almost always whispering, making the voice very soft, low, gentle and mysterious. Almost like another language.