I'm not sure if this has been suggested before, or if it can be done, but I thought it might be interesting if we had some sort of mask to put over a dress-up to make it appear darker, sort of like the shadow items with the knocked back opacity, but for a whole background? Perhaps one could have raindrops? Or maybe there could be raindrops (without the "masking"), sort of like we have the blizzard backgrounds/snowflakes? Hahah I'm not too sure, those were just a few thoughts that came to mind when putting together a dress-up.
Aside from this, I would love to see some more RPG items or "mystical" items like those from the Space Event.