Shifter energy
At least some Jenny Everywhere incarnations' shifting gave off large amounts of “shifter energy”, (COMIC: Makeshift Multiverse) also called “shift energy” (PROSE: Morning After) or “shifting power”. (PROSE: How To Steal Timeships & To Influence Time Lords)
This energy, refined into a beam fired from a cannon, was one of the few things which could harm the Entity. It seemed to be tied into the life-force of each individual Shifter in some way, as it being entirely drained away could result in the death of the subject. (COMIC: Makeshift Multiverse)
Jenny understood shifter hangover as being caused by “burning through a lot of shift energy really fast”. (PROSE: Morning After)
It was possible to harness a shifter's dimension-transcending powers against their will, draining them of energy. For instance, Doctor Brain's Portal was an interdimensional portal which drew its power from a captured Jenny Nowhere. (COMIC: Meanwhile, On Earth)
Shifter energy was known to appear as a shimmering gold, (COMIC: Makeshift Multiverse) rainbow-coloured, (COMIC: Jenny Everywhere in the House of Terror, etc.) or green. (COMIC: Zed Vs. The Travel Agent)
Jenny Nowhere once made pragmatic user of her “shifting power” to make herself glow so as to see the controls of a ship which had been plunged in impenetrable darkness. (PROSE: How To Steal Timeships & To Influence Time Lords)
