Ok soo this exploit work on and please read MANGOS (JUST MANGOS) 3.1.3 last rev i think :P ok soo what you have to do:
1) Make a DK and put 1 talent point in NECROSIS ( Necrosis - Spell - World of Warcraft ) talent (first just 1 point next if wont work put full points)
2) Go to nexus and atack an Mage Slayer - NPC - World of Warcraft it will give you and debuff this one: Draw Magic - Spell - World of Warcraft
3) PROFIT now you will see your autoatack (necrosis talent) will give u BIG BIG DAMAGE. :P