I have just realised that Goblin Slayer is the inversion of Frieren.

>Both protagonists are tremendously autistic and function poorly in social environments
>Both are hyperfocused on total extermination of a certain enemy that they consider irredeemable
>Both keep reminiscing about a former companion who died before they realised their feelings for them

>for Frieren, it's a male human and she's a female elf
>for GS, it's a female elf and he's a male human