If you are like me and decided to get this while in the end game, this is the solution for you. Obviously, equip the blood steal shard and make sure you bring your healing potions and ether.(Just in case). Equip the directional shard called Heretical Grinder.(If you want to make it stronger, farm the Blood Grinder Knight). Now warp to the Oriental Sorcery Lab. Go to the Master Carpenter boss room. Right when you enter, invert and stand above him. Then go to town with the heretical grinder shard. Purple blood every where! Use your blood steal shard periodically while you fight him. Check out the video to see how it works in action.