If you have never heard the amazing Japanese band Dir En Grey I suggest you go have a listen on You Tube now. I say You Tube because a: Spotify don't have their best song (in my opinion, posted below) and b: Because they just have to be seen to be understood.
A band that have got darker and heavier over the years but seem to consistently produce great songs. If you enjoy heavy music, turn your speakers and bass right up. Then a bit higher. Then a notch higher. Then play this.