Well, maybe that second idea is a bit too technical for someone unaware of electric engineering after all and also for a drawing but in essence it is where 2 girls are connected to the same current source in parallel so they share the current. they both suffer but survive, but if one disconnects herself then another one dies because now she has to take everything on herself :) also if someone else connects herself then they all suffer even less :)

That probably would works for a character who is sweet and caring if she wants to help someone.
and it could even work as a story where 2 girls are already connected and getting shocked, this sweet girl wants to help, then those 2 disconnect themselves and new girl get shocked to death.


In the drawing I would suggest to connect a single lamp in series, to show the current flow. As it is sort of a contraption where if more girls get connected the brighter it glows :)
If girls get disconnected the lamp gets dimmer but they get much stronger shock
also another idea for electrodes is to attach them to the niple piercings if there is more than one woman.