https://civitai.com/models/583991/arsmorph-world-of-darkness-sdxl-pony?modelVersionId=651556
Morphs everything into DARKNESS
The trigger word is - ArsWorldOfDarkness . It works without it , but the results are better with it.
You can add [Object] Made of Darkness for stronger effect
Start turning everything into DARKNESS in the 0.4 - 0.8 range .
Recommended use 0.8 - 1.2, depending on the model you use and Lora stack.
On the Realistic Pony Models you can go pretty high and still get relatively coherent result.