In terms MC Dälek's voice, he has the perfect mix of calm and passionate. There are few moments where you can hear how much he gets into it, namely the end of Classical Homicide where he practically screams:
"Amplify brainwaves to condense my thought
Bends the dark
Why question my art?"
Production-wise, some of the best samples and beats I've heard in hip-hop. Some really noisy and dirty sounds, which is a good thing to hear compared to the squeaky clean production most mainstream rappers go for nowadays. On From Filthy Tongue of Gods and Griots there is some really weird electronic music, particularly on the 10 minute song Black Smoke Rises. As they have progressed though, they have incorporated some dreamy atmospheres in their music, the title track off Abandoned Language is a great example.
Basically if you're into underground hip-hop or just aching for some rap with actual though and musicality, definitely check out dälek. I'm posting the link for the 3 albums I have but they have one more from 2009 called Gutter Tactics, which I'm yet to hear.
My first hip-hop blog...hopefully next time I will know what I'm talking about a bit more.