An idea for a new cosmetic item.

As for all cosmetic items, obviously, it would need to be absolutely optional and toggleable.

The Fog Of War around Roshan is not "normal" Fog Of War, it has its own little rules (pretty easy to understand).
It would be nice in my opinion to have items that make that particular cloud of fog look like a curtain of smoke, greenish miasma, stormy clouds or something cool.

Obviously if done wrong, with too strong effects it could clutter the view and make it hard to see whether the fog is intact rather than dispelled, but I think it could be done well, subtly, it's as always something that anyone can turn off, and it would give Valve a new universal item along with overlays, weather effects and music.

Another objection could be that normally one wouldn't EXACTLY be able to see where this "special fog" ends, so this cosmetic item would give an advantage.

To this there are two simple solutions:
either giving the default Roshan Fog a distinctive look as well (it would help newbies not to waste wards)
or, if you value the challenge of learning the unique nature of the Roshan Pit, the custom fogs could be all forcibly faded on the sides, so you never quite know where exactly the vision modifier begins/ends.

I came up with this idea because the fact that the fog is "thicker" around Roshan always seemed cool to me, and the "lore" reason why the pit is so dark is probably that either there actually is really a thicker, denser layer of darkness inside (and I'd like this to actually be shown visually), or there is some kind of spell preventing heroes from seeing inside. (and again, this enchantment being visible would be nice).