Thanks to JadeSleuth, don't know how you managed to cut and paste all that. I was only able to quickly skimread. When it comes to blood, for me it's best that I not know all the details.
What's so disturbing about this case is WHY them? The motive just does not make any sense to me whatsoever, in terms of the absurd level of rage required to plan and then successfully commit this sort of horrific altercation. One attacker, two victims plus an unexpected third. After this bloody scene he doesn't just end it and walk out, no he takes his victims with him and later carves them up.
If it's not drugs, can a fetish with gore create a monster like this?