There was a mains-derived EHT power supply for the first TV I repaired when I was 14. It was one of those cabinet-style jobs with a mirror. I worked out for myself that this was mortally dangerous - there was no internet and I had no-one to ask for advice.
The EHT power supply
in this thread sources around 5.8kV
pulsed (perhaps 3.5kV under load), at high current.
It was a low source impedance and for a short period will supply an average current limited by the EHT rectifiers' current-carrying ability, which is now around 3A.
There is around 15kV at 20A in the tank circuit.
The plasma discharge at the antinode can be huge. It is RF, of course, and so travels on the surface of a conductor (or even what is normally an insulator) but it is possible to reach hundreds of Kilovolts. I don't want to speculate on the length of plasma we will see from mine, just yet.