Is it necessary to have a "second character" to act as well? Would it be possible to skip the necessary "guard" action for the second character?
What you're asking depends entirely on the battle system you're using, and the plugins you're using with it.
The default battle system forces you to choose all your party member's actions before they're carried out. There's no way to change that without plugins.
One of the items you might want to customize for that I personally would love to see is the "Evacuate" option, instead of a full-fledged retreat. If you have player XCOM (the new one), you can "Evacuate" characters one by one.
That can probably be done with action sequences, a state, and a plugin.
Simply change the opacity of the battler with action sequencing as I did in the tutorial, and apply a state that makes the character unable to act. Using Yanfly's Selection Control plugin, you can add a notetag called "<Cannot Select: All>" to that same state. I believe this prevents that actor from being selected by any battler. You can try this and see if it works. No guarantees though.
One other item I would love to see is somehow keeping loot, or damage dealt to remain. Example: Escape to regroup and heal.
I doubt I'd make a tutorial for this, because I personally don't like the idea. It doesn't seem very practical. It allows the player to exploit farming items from enemies with very little risk. Not to mention it'd be slightly complicated to make without a new plugin. You're better off requesting or paying for a plugin to be made. Sorry I couldn't be more help. Good luck!
