Can agree that mc doens't seem like a viable choice right now.
Parry doesn't do anything because when you're defending you couldn't care less about your attack and when you're on offence your opponent is very unlikely to hit you. Possible solution: rather than an instant offence income make it a lasting effect like yeild ground, so you can accumulate it while tanking a series of attacks then come back at your opponent. The amount of attack given should be really moderate though because it can be very powerful. Another solution: rather than giving offence at all make it take a little bit of defence away from the opponent.
Shield up costs too much for what it provides, while it really should be just a stance for those with high mc to use. What I would do is just make it cost nothing but have a weight of mc (yes, that's not gonna be useful in valhalla but on the main server you can get some pretty sweet mc gildings and thanes and probably double the cap stat). And make μ modify the duration, lets say current duration times μ^3 , just so if you put 5 points in it you can enjoy not having to refresh it every few seconds.
Sting has far too long cooldown. According to my calculations it's more efficient to use chop than sting in terms of enemy defence depleted per time. And it's far too inefficient to use chop compared to left hook. So sting's cooldown should be like half of what it is right now.
But all in all this combat is already better than what's on the main server, thumbs up to devs.