Berserk, Gunnm Recommendations
Whilst these two have completely different settings, they have many common themes between them. Both Berserk and Alita follow unfortunate protagonists whose troubles seem to go from bad to worse-- pretty much all the time. Guts and Gally/Alita (depending on where you read it) suffer terrible hardship, and through this we see them change dramatically. Both stories are so emotional and amazingly written... but I think it's important to note that they're both really gorey!
While they have wildly different settings (Lovecraftian fantasy vs Cybernetic Sci-fi), they both have strong, captivating, mature seinen stories with lots of violence, gore and death, and they both explore the true darkness of humanity. If you like one I guarantee you'll enjoy the other.
Blood; Gore; Endless pain; Chaotic world filled with destruction and madness.
Different worlds and times, different main characters and their motives for fighting, yet everything is going toward final rampage. Gutts and Gally are searching their sanctuary, a place for ease their minds in distorted world. They won't accomplish anything without fight..