I've just been playing around with this in my game and I'm not sure I've understood what you are trying to do. I can draw a filled circle on my map which is solid black and place it to front and move it around the map like a token. So, everything it passes over becomes hidden. What it doesn't do is block.line of sight through it so someone standing on the far side is still visible, but the only way I can think that would work is if was possible to have moveable shapes that blocked dynamic lighting. This is the test I carried out. The encounter map prior to casting. Conrad is surprised in the forest by a group of soldiers hunting him down. I have already created the 15' zone of darkness on my character sheet and selected 'To the Front' and then copied it ready for placement. Conrad casts 'Darkness', so all I did was paste the zone of darkness onto the encounter page. I don't know how the spell actually works in your game so I've assumed it works like Zone of Darkness in WFRP forming a dark area around the caster. Players view. Then still in players view I tested to see if I could move the zone and place it over the pursuing soldiers. The only thing I wasn't sure about was how to determine who had control of the zone. As the GM in player mode I was able to move it, but I couldn't move Conrad's token so I'm assuming that I had been selected as the player in charge of the zone. But whether that can be changed I'm not sure. Would dynamic lighting somehow ignore this?