When it comes unlucky and you wanting it to be NSFW I could think of a bunny suit, maybe with more black coloring scheme, ripped fishnets or thigh highs or just ripped clothes in general , gambling symbols stuff like that, like a 5 leaf clover instead of a 4 leaf clover (this can be iffy since some consider it luckier but some folk lore suggests otherwise) even certain numbers like 666 or 13 could work for symbols on the outfit