Having seen a certain person's apology, this is a reminder that it is an author's job to research the tropes they put in their book, even if it's ~fantasy~, especially if those tropes relate to living communities, especially especially if those communities are marginalized.
The purpose of fantasy stories is to convey truths about the world and humanity in a non-reality setting. We learn about valor and perseverance and what makes a real monster... from fantasy. So, copy-pasting white supremacist tropes is a replicating harm in your fantasy world.
Even if you don't *intentionally* mean to replicate white supremacist tropes, there are readers who will recognize them and (1) feel empowered in their hatred or (2) feel ashamed and hated in their marginalization. From your made-up fantasy that you didn't research well enough.
And especially to the people saying "it's just fantasy" - so you've never felt personally attached to a character's story as if you lived it yourself? or you've never spotted behaviors or symbolism that mirrored books you love that you felt were good or bad? Exactly.
I'm muting this thread! You can do whatever you want but reproducing violent narratives about marginalized people is shitty and it bolsters violence against us/them and if you choose to be ignorant, you're shitty too 
idc fight your mama

