Think to gladiator fights. They didn't last long, as depicted in video games and movies: Just until someone got mortally stabbed or bled to death.
So let's make a game out of it.
Dodging, Blocking and Parrying become a huge key factor in the game. If you suck at timing, you'll lose.
If you get stabbed, you're probably gonna die. You can't take 638756345 hits. You get one mortal blow.
If you get stabbed in a non-mortal spot, you begin to bleed and your health depletes.
If your arm is sliced, you can't use it anymore. You'd have to switch to your off hand.
If your leg gets sliced, you become barely mobile.
If you get any injury like this, you must finish your opponent in your last minutes of life.
Give yourself armor to prevent these damages, like chain mail, shields and helmets.
Maybe something with no time limit. A TRUE death match.
This sounds just like something my dad was talking about. In fact, you almost quoted him.
But yes, I would totally play that.
If I'm truly in control, yes. If it's just a series of glorified quick time events, no.
Certainly, but I feel that just having that for a central gameplay thing might get boring pretty quickly.