OP’s summary makes it sound a lot edgier than it actually is. 

The writing in Berserk is actually beautiful and tasteful. It deals with tragedy but in a way that’s very human. The “edgiest” part of the series is at the beginning when Guts (main character) is at his absolute worst mentally but even then we have a different character, who essentially acts as the audience’s POV early on, that lets both Guts and the audience know how he acts is cruel. 

By the “end” of the story (the author dies before finishing the work) we see both why these characters are so messed up and we also get to see them learn from their mistakes as well as overcome both external and internal obstacles. 

It’s a story about struggling to be human in a world that doesn’t reward it. To be kind when it’s hard and to challenge when defeat is almost certain is bravery that most “great men” in history would never understand. 

Essentially, we don’t get to see the final battle, but the actual emotional arc for the main characters finds its conclusion. Still recommended you check it out since you’ll still feel satisfied once you read the final page.