The original design by Dondi Bunye, is literally the alchemical symbol for brimstone (sulfur) :
within the alchemical symbol for fire.
Below is the first attempt at the design, which I find quite crude in hindsight. The orientation of the letters is also Don’s idea, and it proved to be quite a challenge. It turns out that there is no accurate way to make text radiate and what-more, twist from a central point.
I decided to include this second picture of attempt number 2 which was botched from the start. I don’t think I need to say what went wrong:
And finally the main picture above is the approved attempt no. 3