I could just make a fake actor and put it in reserve, or make an actor with no moves that is uncontrollable and untargetable... but I don't want to make it look like you're getting an extra fighter and then have him do nothing, that's confusing and annoying for the player.
I also don't use map followers, so it should only be a face in the menu.
This script makes a separate window for guests, so it's perfect.
https://mrbubblewand.wordpress.com/rgss3/party-guests/

But the link's dead. Does anyone have this script or something similar?
Thanks.