Most models will draw the wings behind the character regardless of the direction they are facing. This LoRA is designed to put the wings on their back even when the back is towards the viewer.

This is a UNet-only training, so it should work with the same prompts you would normally use. It is trained against an anime model, so you should use Danbooru-style tagging to prompt it, such as "wings, from behind". There were some NSFW images in the training set, but it should work for both NSFW and SFW purposes.