Everyone knows SEPTICFLESH, right? And most of us know that most the band members have a project. Well, CHAOSTAR is the project of Christos Antoniou (guitars and orchestral parts in SEPTICFLESH) that focuses on the orchestral part of Christos's music.
The project was born after the success of the The Eldest Cosmonaut single of SEPTICFLESH. This single was more into classical music, away from the music path of the band.  So, anyone who doesn't know the existence of that project I have to say that there aren't any Metal parts in it. But that doesn't mean that you won't find strong parts here that are full of emotions.
This is not a new album since Underwolrd includes seven remastered rare tracks and four new ones. The music that Christos composed, is full of energy and power. The experimental parts are binding beautifully with the classic forms as heard in Elegy with some Metal breaks or in Adagio, where the vocals remind me of TIGER LILLIES in some parts. Keep in mind that that this is not an easy to listen album. You have to listen to it many times to get the feeling of it. The lyrics, dark as they ought to be and blend nicely with the whole atmosphere of the album. As for the voices of Nathalie, Maya and Sappho, I believe that there were the best choices while Spiros shines in Misery's King with his performance.
Actually, this album is a way to see the other side of Christos Antoniou and his ideas away from the Metal territory. Unfortunately, I have to put some labels in my attempt to help get an idea for this release, especially if you are not familiar to CHAOSTAR. If you are a Metal fan  that likes classical music too, you will dig it. As for the others, it would be a good idea to start with all the other albums of the band and get into this one.