Hey all, I found another titanite slab within the Artorias DLC a while ago and thought I would share the location with you all. Remember, this is a standard, non-coloured shard and can be used to upgrade standard weapons to +15 or lightning/crystal weapons to +5.
First, make your way through the Royal Wood until you reach the Knight Artorias mist door location. From here turn around and head down the path into the riverbed gully. Continue along this path, slaying the few undead dogs you encounter along the way. You will now reach another mist door (depending on your progress within the DLC storyline). *potential spoiler*
If you enter this door without progressing a particular part of the DLC storyline you will be killed. So make sure you don't have a lot of unspent souls on you, or humanity you do not wish to lose. Before entering also make sure you remove all items of armour and weaponry as you will need maximum speed to reach the slab. Now climb down the ladder (or jump down the outcropping ledges) and sprint across the arena to the waterfall on the opposite side. The chest is hidden behind this waterfall and you should just have time to open it and retrieve the item before being killed by dragon fire.
