Conan

Cheese-assest boss I've fought in a long time. Unblockable, High Damage, often unescapable combos, ridiculous melee range, and extremely resistant to damage. If you get hit by his stun kick, you consider yourself lucky. (I'm also doing this on HARD)

The combo Deadcolt x360a posted above works great, I even sometimes go a full XXYYYY in phase 1. My problem is I can't seem to corner him.

Bonus damage. Lure him all the way to the north end of the room, run back down where there are two water jugs. When BC is approximately past the brown rug, launch a jug at him. It should bounce off the ground, causing BC to stop blocking and get hit. This move is odd because the damage it does is variable. I hit him once for what must have been 25% of his life with a single jug, but most times usually around 5%. You can do this for all the jugs in the room (in all four corners). I haven't hit him with any boxes yet because they're too close to the center, and BC closes the distance before I can throw it.

Phase 2 was easier than phase 1 for me. Found his moves to be more predictable and easier to dodge.

There is a checkpoint between phases. If you die during phase 2 you just have to restart phase 2.

i agree with the above solution as far as using the XXYY combo in dual weild for the first form however the second form i found to be much more tricky to attempt to use the same strategy. so i found an even easier way. there are several pots scattered around the room. pick one up and wait for him to glow blue like hes about to throw the balln'chain attack and throw the vase at him and immediately roll to a side. he not only will not be able to block the incoming vase but if u time ur roll right 90% of the time he will miss u with the bolas attack. it only took me 3 vases and one box to kill him (on HARD mode) and i didnt take any damage!
EDIT:
On my replay in KING mode i found this strategy to be not as effective. I did, however, discover that the long table at the northmost part of the room can be walked behind and BC will just stand on the other side of it. A possible solution, if ur having problems beating him, would be to just stand behind the table and use armor power to whittle away at his health (assuming u have unlocked the unlimited AP cheat). I also found this boss fight to be very glitchy. For instance, on the second stage of the battle, instead of throwing his sword away and gettin out his mace he kept the sword and was invincible! lol And another reload of my previous save his lion was invulnerable to even armor powers...idk what was up with that tho... if you have and questions or something to add feel free to comment im always open to advice!

When you fight this boss the fight is divided into two stages. If you're quick (and lucky) enough you only have to fight him in stage 1 and skip stage 2.
How to do this:
When his health drops to almost none in stage 1 you get a short button sequence (actually it's only ONE button) if you're quick enough and press it, Conan finishes the fight. If you miss it you'll have to fight stage 2 and you can't go back because there is a checkpoint between the two stages.
I only had to fight him in stage 1 but I think it was more luck then skills that ended the fight when I saw the button-prompt.
Good Luck.

If you want a simple way to do this make sure you hold the Bone Cleaver in acorner and dual wield XXYY on him, he blocks the first two but the YY part breaks his block and gets him, it's fast enough that he can't hit you inbetween attacks..

This boss fight was such a pain in the ass, especially on Hard. This is, quite frankly, the cheapest boss you'll encounter in Conan. Luckily, I found a strategy that works quite well for me, on both stages of this fight.

Make sure you are dual-wielding two axes. At the start of the fight, your first priority should be the lion, so either use a Rain Of Fire or use Stone Magic on it, then quickly smash it to bits. EIther way, the lion should be gone and out of the way. Once that's accomplished, it's time to face the music! Make you are out of reach of the Bone Cleaver's assault and throw one axe at him. He'll automatically block it. This should give you a little breathing room, so roll towards him, then do a quick YYY combo on him. Sometimes, you may be able to pull it off, sometimes not, since you'll get hit with the bolas and will have to break free by rapidly pressing B. Either way, make sure to either find that axe you threw and retrieve it off the ground or head to the axe rack and grab another one. If you get hit and are almost out of energy, quickly run to the jars and smash them for the green runes.

If you do this and can get through the hardest part of the boss fight, congratulations! The second half is actually a lot easier than you may think. Continue to use the strategy above, but in case he doesn't throw his bolas at you and whips out a ball/chain attack on you, immediately roll the opposite way to avoid getting hit, then grab the axe. Once again, stay out of range, throw one axe at him. Hopefully, the bolas animation will flare up and you can quickly roll in and get in three hits. Maybe even one, if you are lucky enough until he gets you with his bolas.

Rinse, wash, and repeat until you finish him for good. I am unsure about King difficulty just yet, since I"m playing this on Hard, but this is the easiest, risk-free strategy that works very well and I hear it works for both difficulty settings, or so I'm told! If you need to see how it's done, check out the Youtube link I attached with this post. Credit goes to ghcheezball for creating and posting this video for the public to view and see what needs to be against BC2.

Have fun and good luck!

Beating Bone Cleaver II on the higher difficulties. This method takes a while, but is by far the easiest way to deal with him as it is relatively risk free. To pick up a weapon/object is RB (either from a weapon rack or recovered from the floor) and to throw the weapon/object is RT.

PHASE ONE:
Start by using the Rain of Fire armour power to take out the lion and do minimal damage to BC2 himself. Once you are one-on-one, you will need to put some distance between you and the boss and grab a water jug or wooden crate. This is the trickiest part. You need to close to a distance just outside his attack range and circle him. Conan walks very slowly when carrying an object, but Cleaver will not attack until you are within range and you can prevent him closing in on you any further by circling. He will circle too though you may have to change direction on occasion to prevent him rushing up. Every so often he will throw his bolas at you. There will be a blue energy flash just before he does, at which point you need to quickly throw your object at him. If the timing is right (and it won't be every time, but you should get a couple of decent hits in) the jugs in particular can be very damaging to him, taking up to a quarter of his health. Once you have used up all the boxes and jugs, equip dual axes from the weapons rack. For the rest of the fight the strategy is identical; circle Cleaver at close range (but outside of his attack range) and whenever he powers up to throw the bolas at you, throw one of your axes at him. If the axe throw is timed right, it will take out the bolas as well as inflicting damage on the boss. If it is not timed right, you will either do damage to Cleaver AND get caught by the bolas, or simply get caught by the bolas if you were too slow. When caught by the bolas, break free with B a roll back to your circle distance and try again. After a successful axe throw, immediately recover the thrown axe as the weapon rack has a limited number for you to replenish from and between phases any axes on the floor will disappear. Repeat until Cleaver's energy is depleted, grabbing health from the breakable jars if you need to.

PHASE TWO:
Almost identical to phase one, though this time there is no lion to help Cleaver out, and there are no jars or crates left to help you out. Move in on him again to your circling distance and repeat your axe throw technique. On occasion he may close and attempt a ball and chain attack, but do not despair as this too can be interrupted by a well-timed axe throw. If he is going for a shockwave attack rather than a simple attack you will have to jump to avoid it as you have no doubt learned to do by this point. Eventually, circling, throwing and collecting your axes will chip away at his health until he dies, just as it did during phase one.

Now sit back, enjoy Conan's trademark brutal finisher cinematic and Robert is your father's brother, Achievement Unlocked!

Here's another video for those who prefers video guide.