1. Using blood bending, you can ONLY block ones bending...like Amon
2. Using energy-bending, you can give AND take bending...like Aang, Korra, and the Lion-Turtles
Energy bending bends one's own energy to do anything in the body...kindda like Scar's alchemy in FMA
Blood bending can only take bending by manipulating the blood/water in the body and attacking/severing/etc. certain energetic connections...kindda like the Hyuuga clan in Naruto, restoring and severing chakra connections, but in avatar it's chi connections because if lightning bending works on chi (as explained by Iroh while trying to teach Zuko lightning bending) then theoretically ALL bending works on chi.
2. Using energy-bending, you can give AND take bending...like Aang, Korra, and the Lion-Turtles
Energy bending bends one's own energy to do anything in the body...kindda like Scar's alchemy in FMA
Blood bending can only take bending by manipulating the blood/water in the body and attacking/severing/etc. certain energetic connections...kindda like the Hyuuga clan in Naruto, restoring and severing chakra connections, but in avatar it's chi connections because if lightning bending works on chi (as explained by Iroh while trying to teach Zuko lightning bending) then theoretically ALL bending works on chi.