If you're looking for anime similar to Goblin Slayer, you might like these titles.
When Haruhiro awakens, he's in the dark surrounded by people who have no memory of where they came from or how they got there. As the darkness fades, a fantastic new world called “Grimgar” appears before them and their adventure begins—but first, they'll have to choose their guild, class, and special abilities.
Both are Fantasy animes about adventurers who fight goblins, goblins,goblins, goblins and even more goblins, in both the fights against the goblins are very intense in are never easy for the adventures.
Neither of these is your typical perfect-isekai anime. Both deal with some dark topics and don't idolize the troubles characters face
Born beneath the gallows tree from which his dead mother hung, Guts has always existed on the boundary between life and death. After enduring a terrible childhood, he spends his adulthood in brutal combat, pitting his strength against others in order to build his own. Life is simple enough for Guts until he meets Griffith, the inspirational, ambitious, and beautiful leader of the mercenaries, the Band of the Hawks. When Guts loses to Griffith in a duel, he is forced to join the group, and, despite himself, finds a sense of camaraderie and belonging amongst them. However, as Griffith leads his soldiers from victory to victory, the bloody wars and underhanded politics reveal a side to him that nobody quite expected. Can Guts, a simple warrior, defend those who have come to mean the most to him, all the while struggling not to lose to the darkness he has carried with him his entire life?
Both anime have a dark atmosphere, beings in this world are brutal. We gets lots of fights, action, gore, blood and rape.
if you find all the dark, edgy nature of new, then check out the original take on dark and edgy before it became known and possibly slightly cliche and that being Berserk. Berserk took to the stage of rape, gore and violence and then comes along Goblin Slayer with the same atmosphere with a modern twist.
Under the rule of a tyrannical empire, Tatsumi, a young swordsman, leaves his home to save his poverty stricken village. He meets a girl named Akame, an assassin who was bought, brainwashed and trained to kill by the Empire. Akame is a member of the secret assassin group called “Night Raid” who use special weapons called Teigu. Together, Tatsumi and the members of Night Raid confront the corrupt empire.
Naive people go to city, hoping that their life will go great, they'll do a few things, make money, become famous and... And then life surprises them, people die, lots of blood, MC gets little trauma, then there's a hero saving the day. Done.Basically - naive characters, op characters, blood and gore, quests and dark atmoshpere of the world.
Nature made Ash Lynx beautiful; nurture made him a cold ruthless killer. A runaway brought up as the adopted heir and sex toy of "Papa" Dino Golzine, Ash, now at the rebellious age of seventeen, forsakes the kingdom held out by the devil who raised him. But the hideous secret that drove Ash's older brother mad in Iraq has suddenly fallen into Papa's insatiably ambitious hands--and it's exactly the wrong time for Eiji Okamura, a pure-hearted young photographer from Japan, to make Ash Lynx's acquaintance...