More dynamic smoke

[Studenterhue]

I like this idea; it creates an interesting strategy for chemsmoke beyond "this much smoke powder for a cloud this size". You have a lot more legitimate, valid options: you can make a hellsmoke that trades off range for maximum helldeath or one that goes really far but is much less deadly, and control how long each will affect the person in the cloud. These tradeoffs could actually give some real depth to chemistry.