My Marx Generator gives pretty juicy sparks, but at about 1 every 2-3 seconds from a Flyback
transformer, it's not the most intimidating. Not a lot of power can be gotten from a Flyback (except
perhaps in ZVS mode).
So I hooked it up to a beefier 15kV supply - a Neon Sign Transformer rated at almost a Kilowatt. A
couple of microwave oven diodes rectified the AC into the necessary DC.
Check out the results...