Slipknot

Well, I listen to them because of their aggressiveness, and whether it's more complex or not is debatable, but both are masters of the "Metalcore" style.

I found and downloaded an album from 2005, released by Madway, and honestly, it doesn't smell like metalcore. I wonder if I need a different album? Recommend something.

Otherwise, it's more like nu-metal, but with aggression – closer to the style of KoЯn,
this is probably a well-known mix called angrycore – something like that.