What does charged disruption actually DO?

I tried testing, and I have no clue what it even does. Does it increase the amount of charge you get from doing damage? Tested that, no. Does it increase spirit blade damage? Tested that too, no it doesn't. Does it make the spirit blade gain charge from all damage sources, including party member damage? Tested that TOO, and it doesn't do that either. Does anyone know what this seemingly nonfunctional upgrade even does? Even the wiki just has the in-game description, which tells you nothing useful (hence me having no idea what it does). Has anyone checked tooltips or done testing to know its use? I probably won't use disruption field at all, but I might if the new upgrade is useful. But my testing for the last half hour has confirmed a whole lot of nothing, so I can't even know if it IS useful. Maybe it really is a broken upgrade, but I doubt it.