According to the leaflet following Spawned from Hellfire and Brimstone from Singaporean death metallers Vrykolakas the music is rooted in long running bands like Grave and Incantation and I tend to agree with this. It's easy to hear the references to Incantation which mainly appear in form of the ultra low vocals and the dark and filthy production, but I wouldn't say the band sound like a clone of any of the aforementioned as they also incorporate a bit of black metal here and there.
The music is varied in terms of pace, but also riff wise. All the songs are relatively short and yet Vrykolakas appear to have put a lot of different riffs in each song. I don't really have a whole lot more to say about this effort other than if you're looking for some serious underground stuff then Spawned from Hellfire and Brimstone is definitely worth the purchase. The CD might not bring anything that hasn't been heard a million times before, but Vrykolakas certainly does it in a convincing way. I can only recommend checking out this band.