Having read this thread, I thought it would be a nice challenge to see how an SF would approach this fight, so I wanted to see if my raven 3 SF would be able to clear the first boss.
As people have mentioned earlier, there are four basic skills and I'll mention what I did for each animation:
Full circular yellow aoe spin: Block with 1 skill for 2 seconds, if you have the hongmoon skill it recharges the chi on each hit until it reaches 5 stacks and you just press V after the spin is finished
Uppercut move: Blockable, but just circle around the boss to avoid it
Half circle red aoe: Unblockable, use Q or E to avoid
Linear rectangular yellow aoe: Blockable, but just circle around the boss to avoid it
Basically you want to be continually circling the boss when you're not blocking (just hold onto A or D) so you don't have to even worry about moves 2 and 4.
Roughly every two full rotations (it won't be exactly two rotations, it could happen in between any of those four basic skills), he will say "Face me like a real warrior". He will charge at you to stun and if successful he will grab you. The stun is blockable so I start to put up a preemptive block before the next basic skill and when it's getting close to two full rotations. If he continues to do his basic skills instead, just move to cancel the block and continue dpsing (or just block the attack if it's a yellow attack). If you do get grabbed, either just stay grabbed if the add is not a threat, or immediately tab escape if the add is about to be a problem.
As for the add, when he is not incapacitated, he will either plant a red aoe bomb or do a half circle yellow aoe. Since you should always be circling the boss, you should easily be able to walk away from those two attacks.
When the add starts rolling away and says "I got something for you", you have two options:
SS (puts you into ranged stance) towards the add and turn around to press 4
Dash on the 2 skill in melee stance, and use either 3 or 4
If you're too far from the boss, he will do a jump stun, but if you managed to cc the add, that's better than having the add heal the boss or continue to throw random attacks at you.
In the end, I was only doing about 40k dps and I have high ping, so I had to stop attacking way in advance in order to do the mechanics properly.
Hope this helps, and good luck!