I'm not sure if I understood you properly. But on the charge tp by damage formula, you can use "this" without qoutes to refer to the current battler receiving the damage.
Otherwise you will need to explain better what are yountrulying to do and on what moment of the battle.
I may take a while to answer you, because my I'm away from my computer
const isActor = this.isActor()
if(isActor){
// Do your thing
}

