IDk, 1.21 jigawatts ? He was able to move so fast Anakin didn't even know what was attacking Mace Window at the beginning of the end for MW.
Electrons in massive gravitational fields get relativistic boosting. Also in ultra dense/compact plasma's, electrons can get R.B'ing.
The Emperor seems to just do spark gap discharging, of slow electrons. I wonder what the x-ray and gamma-ray spectrum of this would look like.
And now watching movie LS battles looks just like acting/play-fighting compared to real-life LS battles or in video-games on top of the line rig's