Clouds

[matastrb]

I think some random white clouds could be spawned in the map of CTF similarly to shields. In effect, this action reduces the visibility of both teams, hence makes matches more unpredictable. Thunder clouds could also be there to deliver some small damages to players.

I did some quick google search and found some implemented cloud codes
here (this includes also thunder clouds and michael bay's effects)
https://www.clicktorelease.com/code/css3dclouds/
and here
https://github.com/benpryke/Cloudgen.js

Or perhaps simpler (without css effect), for each player except his/her client, every plane within the radius of a cloud spawning point is invisible.