Here's an idea for a passive gauge option. Feel free to suggest anything that can improve on this idea.

Edit 5/8/2021: Have option to define Max Points of passive gauge "Max Gauge"

Have some kinda toggle to define if a gauge is passive or not.
Define if a gauge is a passive drain (stun meter from street fighter) or a passive gain (the guard gauge from naruto GNT4)
Maybe put this option in character editor window to define each gauge options. this can allow different values for each character

Passive Drain (Meter will decrease over time, the will make the UI gauge bar visually decrease)
Max Gauge - Maximum value the gauge can have (good for stun meter)
Drain per second - the drain rate
Delay before drain - Delay before a gauge starts draining after a change is made. e.x. if gauge gained 10 pts wait for delay then start drain
Move 100% gauge - Use a move info file to do something when gauge hits 100%. e.x. play a stun or block break move. The move info file can also handle resetting the passive gauge to a certain value with current gauge options
Stance 100% gauge - change stances

Passive Gain (Meter will increase over time, the will make the UI gauge bar visually increase)
Max Gauge - Maximum value the gauge can have (good for stun meter)
Gain per second - the gain rate
Delay before gain - Delay before a gauge starts gaining after a change is made. e.x. if gauge lost 10 pts wait for delay then start gain
Move 0% gauge - Use a move info file to do something when gauge hits 0. e.x. play a stun or block break move. The move info file can also handle resetting the passive gauge to a certain value with current gauge options
Stance 0% gauge - change stances