I feel like over-indulgence of anything is bad for your soul. However, I've been listening to, playing and being in the metal for the last 30 years, and this is what I have seen:
I see 3 types of people who have opinions on heavy metal and other forms of aggressive music.
1) people who don't listen to it or maybe don't understand it. It is ok for you to abstain from it and call it devil music or bad for your soul.
2) people who have a more mainstream or an older view of heavy metal or a more shallow experience to it. Someone asks you to name 5 metal bands and you say Metallica, Slayer, Slipknot, Tool, Judas Priest. You understand that "rock music" is "all about sex drugs and rock and roll". Its "angry music for angsty youth". "Black metal is metal about Satan and the darker aspects of life, with purposely bad recording quality". You choose heavy metal because of its image, its bad and you feel bad. These people may try listening to Christian metal if you have a faith or are seeking today, or try abstaining from it to change your mood. Example: "I like Slayer since it sounds evil. Now, I've grown up/got saved, the music or lyrics bother me. So I should give it up to live better/live with God"
3) people (often men) who have something missing in their life, and seek to fill it with heavy metal. You are tired of "happy pop music", so you desire doom metal to tell you the truth. You are tired of an abundance of femininity, so you seek to find masculine metal music. You are tired of simple, dumbed down culture, so you seek out technical progressive metal. As a white European man, you have no "culture" or "heritage" so it amazes you that a group like Batushka has Eastern Orthodox, Eastern European culture to their music. It amazes you that there are metal groups that incorporate viking or other ethnic/historic/folk elements that you are currently missing being a man who is just told to work, pay taxes, and be a "toxic male" in todays corporate america while living in an apartment in a major city. If you, through introspection or some means, notice that you do listen to heavy metal to fill some need, I would embrace it and talk to God about it -- we've all been made unique by the Creator and this could mean some are more melancholic, some are more creative, some are more prophetic, etc... And the music could prod you into new life paths: I listen to orthodox Polish heavy metal -> I should start going to church. I listen to very technical music like Meshuggah -> I should let's say quit my simple retail job and pursue some mentally challenging math, engineering or tech career. I listen to folk metal -> I should move out of my studio apt in NYC or Chicago and buy a house and fix it up and get out into nature.
In the past, I have been in the front row of some blasphemous heavy metal bands like Behemoth, Black Dahlia Murder, Aborted, and so forth. People in group 2 might be there just to say "yea, rock on, I hate God, hail satan, down with the system, kill people I hate" and so forth. People in group 3 might be there to say "Play faster and louder and more extreme. I am seeking higher knowledge, wisdom, a deeper experience than I get in my dull day to day life".
So while group 2 might associate aggressive music as destructive and bad for the soul, but they like it (it feeds their flesh nature in Christian terms), if you notice that you are part of group 3, you might keep the music but let it propel you into making external life changes that you are subconciously seeking out.
I am an advocate of Christian heavy metal or even heavy metal in general since being a straight, white, masculine, rational, introvert, thinking/smart, independent man is looked down upon in today's America or today's modern evangelical church in America. Of course, you can take it too far and people sometimes don't grow up -- being "stoners" and clutching on to being a 18 yr old metal kid.
To me, if I had a child, I would rather him get into the heavy metal group Death's song "Flesh, and the power it holds" or Alice Cooper or Impending Doom or something to say "Look, we are all going to die. We have a flesh/sinful nature, and could have power over us in this life or the next. Think about it" rather than "just go along with culture. Girls, guns, money, fun times, party it up" of whatever today's big pop hit song is.
I think in a perfect world, we would all listen to classical music. However, I feel like God uses/can use some bad events or types of music or musical experiences to push some people into a direction they should go. Example: there was little "end times" Christian music. Then, Savior Machine and Crimson Moonlight and Armageddon Holocaust and those types of end times preaching Christian metal came out, then people listened to them and starting reading Revelation and getting right with God. They may have been previously drifting along or their pastor was preaching "Don't worry about those scary books of the Bible. I'm not trying to scare you. Just like that movie All dogs go to heaven, we probably will all end up next to our dogs and cats who passed away playing harps on a cloud forever". We are not to focus on the end times and the beast and all that. But, God had to use scary heavy metal to get a point across to some that suffering can exist in this world and the life to come, whereas your church of God might just only let God say "Be nice to everyone and try to be loving and everything will probably go alright for you. There's no hell or devil or end times judgement or cancer or anything scary in life, just listen to some happy worship music". So God might say "Ok, heres some war. Heres some heavy metal. Heres some storms. Some temporary things to let you know life is not always easy and perfectly controllable and comfortable" as well as giving us blessings and joy too.