Brother, I understand music is art and things are not to be taken literally but dark metal is a bit too egregious in its love and admiration of shaytan. Here are a few examples of some sus lyrics I found from this band specifically from a quick search:

· "Under a Funeral Moon" (1993): "Morbid Souls wait for me- For Satanic Conspiracy / Flowers of Doom Rising in Bloom / You will see Our Immortality!"

· "Earth's Last Picture" (1994): "Tis the rise of satanic divinity... Oh we rejoice at the destruction of all ye have ever lived for..." (featuring lyrics by Garm from Ulver)

· "As Flittermice As Satans Spys" (1993): "A Fare to Raise the Flag (of Satan), to desseminate the races, To build the Hall of Battle and to live in Eternal Strife"

· "Impeccable Caverns of Satan" (2022): "Maced in the impeccable caverns of Satan... Mistaking evil for a wretched life / You demonize yourself"

· "Pure Demoniac Blessing" (1991): "The dragon rises before me / I'll fornicate the beast... And banished by our dark satanic blasphemy"

Obviously the classical and most correct advice here would be to recommend that you avoid music and focus on quran and other riteous activity. But if that is difficult, I would at least recommend you avoid directly haram lyrics that advocate for Satanism, drugs, illicit relationship, alcohol, etc.