Banner Saga-esque Battle System?

[JamesOfJames]

Hello all - my searching has gone fairly deep, and I'm finding scripts similar to what I'm looking for, but not exactly. For those that aren't familiar with the combat mechanics of the Banner Saga, there's two salient points. First, your health and your attack power are directly linked - as you become closer to death, your combat effectiveness diminishes. Secondly, (and because of the first point,) it is often in your interest to leave an enemy alive but grievously hurt, because the mechanics dictate that the player's side and the enemies will alternate turns as long as there are at least 2 fighters on both sides. Thus, an effective strategy is often to maim one enemy, then focus on the next and so on, so that their battle order is cluttered up with ineffective fighters.

I've found stamina/charge battle systems, battle systems where each side takes turns, and so forth, but I've not found a system where each character & enemy take turns in any order but by agility or something similar. If there's not a system that has each side taking turns as I've described above, does anyone know of a battle system which allows the order to change dynamically so that I could alternate turns? Or perhaps a battle system where each side has their own turn order?

Thanks for any scripts anyone can point me towards!