To reach this boss, enter the previously mentioned valley in the Royal Wood. The slope leading to it is just before the Artorias boss arena. Proceed past three dogs, through the fog door, and down the long ladder to your left.
BOSS – BLACK DRAGON KALAMEET
First, understand that Kalameet’s breath does not count as fire. It counts as magic, so equip a shield that has high magic resistance as well as similar armor.
If you move towards his front right side, he’ll almost always swipe his head from right to left and follow up with a left to right. Roll left under the first swipe, then left again to avoid the second. Now take lock-on off and hack at his legs a few times. You can see us do this several times during the video.
It's also great to use long range spells or miracles (we used lightning bolts). You are safe to use them when he does his arcing breath (if you back away far enough), when he does his short range breath (if you dodge to the side first), his long range straight breath (if you dodge it), and just after his flying dive attack. Again, you see us do this throughout the video.
The best possible time to cut off his tail for the Obsidian Greatsword is immediately after he does his downward tail slam. It’s hard to coax him into this move, as you have to get directly behind him. The best times to do so are when you anticipate a short range breath attack and run (turn lock-on off) around to his back, or after he does his glide attack.
There are many times during this fight where locking on to the dragon works against you. For instance, if you are trying to dash under him to get in a few strikes, the spinning camera will disorient you. If the dragon flies into the air to shoot flames straight down, the camera may prevent you from retreating to a proper distance.
After the fight, look for a chest near a waterfall in the immediate vicinity. It contains a Titanite Slab. Then, return to Hawkeye Gough to receive Gough's Greatbow.