Is it a sin to draw, write or read violent stuff? No. If it was the Bible would not exist. If the Bible was made into a realistic series following chapter by chapter accurately showcasing the events there would be quite a bit of very violent, bloody and often sexually charged things. Which is why I don’t let my kid read all of the Bible. They are not allowed to read certain portions of the Bible. I censor it mostly by not really bringing a lot of attention to it. Song of Solomon for example is quite a R XXX type of story. It’s genre is romance erotica. It’s meant for adults.
So it depends also a bit on your age what you’re into. A 10 year olds version of violent horror should be different from a 16 years old which should be different from a 30 year old.
I’m a big fan of horror. I even have a Shudder subscription and 99% of what I watch is horror and it ranges from old black ad white horror to the film X that’s still in theaters. I watch horror that’s anime like Higurashi: When They Cry and liveaction. I watch slashers, Creature features, classics, new French wave, horror comedy, dark romances and ect… same for reading books as well. None of it negatively affects me. I’m a vegan who does not hunt or fish and spend a lot of my free time taking pictures of flowers, caterpillars and playing with my cats. When needed, I can be very empathetic or very blunt. Though I will defend myself I’m not hot tempered or needlessly violent. I’ll take quite a bit before fighting back. Sometimes i also will watch a chick flick or family film and equally enjoy it. I don’t listen to a lot of music but the bulk of music is pop like Miley Cyrus and even Taylor Swift. So while 2-3 hours of my day is listening to horror podcasts ( currently going through the radio dramas of the 1930s-40s of the “ Lights Out “ series that was released recently on “ old timey style podcasts showcasing work of the past). And though I watch 1-2 horror films or episodes a week I also am completely functional and don’t have some crazy issue.
So drawing violent stuff is not problematic. What can be problematic is fixating on violence as a main go to problem solver. You also need to be considerate of others. Don’t draw some girl from your class being brutalized without consent, or even avoiding it with consent. Don’t fixate on drawing out your hatred for others through fictional violent imagery. Those things can harden a heart.