I had this idea that I could stuff a tiny tesla coil into a mjolnir and end up with a really cool prop... I had seen some videos of [Staci Elaan] showing off her battery-powered coils and I really liked her results. I figured, with her experience, she could probably do a better job than I could on getting the most bang out of a small package. She was happy to be involved and delivered a small 12v powered coil for me to work with.
You can see a ton of photos of the process over at Hackaday, including the HV coil and the RF inverter, and how they fit into the small space afforded by the hammer. But here's a neat "making of" video: