To make a script that can use current party leader face in generic dialog.

I would like to draw multiple faceset on generic dialog.
An example: My game consist of 40 main characters that switch every so often. I want the system detect the change in my main character and use whatever the actor's face set is for the TEXT dialog.

How would i go doing that?

So far my idea is that, i will set a common event that is on parallel. with conditional branch of each character. Giving 1 variable to each character.

Then i would set something lke

def actor_change
v = @game_variables[5]
if v == 1 draw_actor_face(actor, 0, 0 size = 96) ....etc
end
end

However, i don't know how to get the current actor's face and put it into works. (i am a newbie with scripting)

anyone have any idea? And also i thought about that...if this really works, i also need a on/off switch as well. so that the other NPC's face won't get overided.