Shadow of Mordor Combat, like cmsurfer said, just wont work. Its flashy, easy and looks good, but its because he's fighting npcs. If one player could just stand in the middle of a bunch of ninja and take them all out with 1 button press each, I'm sure you could see how that would be a problem. I think that taijutsu should have a simple but skill based combat system, similar to dark souls.
For Taijutsu, No dedicated "Hold this to block all incoming attacks" button like say in mortal kombat. There should be a timed block, where if you time it correctly say you block a punch, if you time it good enough it blocks the attack, but if you time it perfectly it sets you up to perform a throw on the enemy.
Kenjutsu could work similarly, use the block button to block incoming enemy attacks, blocking thrown projectiles if block is activated just before contact. However I believe there should be a parry ability, that allows you to take a risk and parry your opponent knocking their weapon aside for you to riposte/counter attack. If missed you'll probably take a pretty harsh blow, if landed you get to deliver one. Risk/Reward kind of thing, plus it adds skill to the skill trees, because if its just straight up spam mouse button, its hard to say who's a better swordsman.
Just the idea of watching two people run in a circle throwing mundane punches at eachother until one dies gives me a headache. Of course thats somewhere to start I'm just thinking for the endgame. Fast paced, flashy skill based combat.
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