Yeah, that was my intention, blood magic + empower + glass cannon works well for kiting if you use teleport on the off-hand to get away quickly and stack all of that DPS with mp or hp leach (even 0.5% would return the HP bar to full when your resulting DPS hits over 1.0M).
Edit: I was meaning in terms of Blood magic and Empower/Glass Cannon, they reduce the total HP first, then blood magic adds MP, in this case, if HP = 5000, and MP = 20,000 then the reduction would be -50% HP, and then + 20,000 MP resulting in 22,500 HP, instead of 12,500 HP.
I would have thought that they would have intended for HP reduction or % increase in HP to take place after all other changes occurred (i.e. blood magic)