I don't know how to script but I know how some basic functions work. I was thinking a system for frames. Like once you attack, you have 60 frames to do up a combo, Maybe they'll be a Combo gauge above the player to show how much time the player has to do a combo, and once the combo gauge is full the player will freeze for half a second, this is the players chance to guard.
If it isn't too much to ask for, I was thinking the enemies can do combos too and guard when their combo are finished.
This will be beyond awesome if you could do this