I think anything that increases the skill ceiling is desperately needed in this game.
If I had a magical wand I would personally give each fighter more combos and deeper variety to their attack options first, but some sort of parry system would definitely be up there too in terms of things that would help.
I'm a big fan of "reactive" parry systems, where you need to time it with the enemy attack for maximum effect, as opposed to holding down a button to block everything. I'm excited to see what they have implemented.
